Infrared reflective laminate

ABSTRACT

The infrared reflective layered product can reflect infrared radiation with certain wavelengths to prevent heat accumulation and, at the same time, has excellent heat resistance. The infrared reflective layered product comprises a layer (B) as a base layer, a layer (A) layered on one side of the layer (B), and a layer (C) layered on the other side of the layer (B).

TECHNICAL FIELD

The present invention relates to a layered product having a property ofabsorbing a visible light and reflecting an infrared light so as toprevent heat storage when irradiated with light and excellent in heatresistance, and further relates to an infrared reflective layeredproduct excellent in weatherability, hydrolytic resistance andflexibility. Also, the present invention further relates to an infraredreflective layered product which is excellent in water vapor barrierproperty and/or prevented from curling.

BACKGROUND ART

Recently, there is a growing demand for solar cells that have beennoticed as energy supplying means alternative to petroleum which is acause of global warming. With the increase in demand for solar cells,stable supply and cost reduction of parts such as back sheets for solarcells have been required, and also there is a growing demand forimproving power generation efficiency of solar cells.

Back sheets for solar cells are layered on an encapsulating resin faceafter encapsulating a silicon cell under the glass plate with theencapsulating resin such as ethylene vinyl acetate resin.

Conventionally, as the back sheet for solar cells, a white thermoplasticresin sheet layered on both faces of a polyester sheet has been used inorder to improve reflection of sunlight so as to improve powergeneration efficiency of solar cells (Patent Documents 1 and 2).

On the other hand, since solar cells are arranged on a house roof, backsheets for solar cells colored in dark colors such as black have beenrecently required from the viewpoint of design.

However, the conventional black back sheet for solar cells is generallymolded by kneading a carbon black into a resin, and thus the carbonblack absorbs sunlight and increases the temperature. As a result, powergeneration efficiency of solar cells is lowered, and durability may alsobe lowered.

On the other hand, a back sheet for solar cells with low heat storage,which is obtained by kneading an inorganic pigment having an infraredreflecting property in a rubber-reinforced vinyl resin followed bymolding, has been also suggested (Patent Document 3), but furtherimprovement in infrared reflectivity has been required.

In addition, a back sheet for solar cells provided on a surface thereofwith a black resin layer containing a perylene pigment and having alight reflectance at a wavelength of 800 to 1100 nm of 30% or higher soas to reflect near-infrared light and prevent heat storage is alsoproposed (Patent Document 4), but since the substrate thereof is made ofa polyethylene terephthalate film, it is inferior in weatherability andhydrolytic resistance disadvantageously.

Moreover, since the back sheet is layered on an encapsulating resinsurface of solar cells as mentioned above, it is required to have awater vapor barrier property in order to prevent vapor from invading theencapsulating resin from the back sheet and deteriorating siliconecells.

-   Patent Document 1: Japanese Patent Laid-open No. 2006-270025-   Patent Document 2: Japanese Patent Laid-open No. 2007-177136-   Patent Document 3: Japanese Patent Laid-open No. 2007-103813-   Patent Document 4: Japanese Patent Laid-open No. 2007-128943

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention

The present invention aims at providing an infrared reflective layeredproduct which has a property of reflecting an infrared radiation with aspecific wavelength so as to prevent heat storage even with blackcolored or chromatically colored appearance, and also, is small inthermal deformation and excellent in heat resistance, and further, isdifficult to hydrolyze and excellent in weatherability even when usedoutside for a long time, difficult to crack and excellent in flexibilityeven in a form of film, and good in processability, productivity andhandleability.

In addition, the present invention aims at providing an infraredreflective layered product which is further prevented from curling.

Moreover, the present invention aims at providing a layered productwhich is an infrared reflective layered product excellent in water vaporbarrier property, and particularly suitable for a back sheet for solarcells.

Means for Solving the Problem

As a result of intensive studies for solving the above problem, thepresent inventors have found that a layered product, which has aproperty of reflecting infrared radiation so as to prevent heat storageeven with a colored appearance and is excellent in heat resistance, canbe obtained by arranging a colored resin layer which is low in infraredlight absorption on one side of a thermoplastic resin layer having aspecific heat resistance and arranging a colored resin layer which ishigh in light reflection on the other side of the thermoplastic resinlayer. Thus, the present invention has been completed.

In addition, the present inventors have found that curling can beprevented when a thickness of each layer of the above layered productsatisfies a specific relation, and further, a layered product excellentin water vapor barrier property can be obtained by arranging a watervapor barrier layer on an outer surface or between layers of the abovelayered product. Thus, the present invention has been completed.

That is, the present invention provides an infrared reflective layeredproduct comprising:

the following layer (B) as a base layer;the following layer (A) layered on one side of the layer (B); andthe following layer (C) layered on the other side of the layer (B).Layer (A): a colored resin layer having an absorptance of a light with awavelength of 800-1400 nm of not more than 10%.Layer (B): a thermoplastic resin layer which shows a dimensional change(s) satisfying 1%≧s≧−1% when left at 150° C. for 30 minutes.Layer (C): a colored resin layer having a reflectance of a light with awavelength of 400-1400 nm of not less than 50%.

In addition, according a preferable embodiment of the present invention,there is provided the above layered product which comprises a watervapor barrier layer (D) layered on the outer surface of the above layer(A) or the above layer (C), or between the above layer (A) and the abovelayer (B) or the above layer (B) and the above layer (C).

When the above layered product does not comprise the water vapor barrierlayer (D), it is preferable to comprise a protective layer (E) on theouter surface of the above layer (A) and/or on the outer surface of theabove layer (C).

Also, when the above layered product comprises the water vapor barrierlayer (D), it is preferable to comprise the protective layer (E) on thelayer (C) side as the outermost layer.

In addition, according another preferable embodiment of the presentinvention, there is provided the above layered product in which athickness (H_(A)) of the above layer (A), a thickness (H_(B)) of theabove layer (B) and a thickness (H_(C)) of the above layer (C) satisfythe following expressions (2) and (3).

0.5≦H _(A) /H _(C)≦1.3  (2)

0.4≦(H _(A) +H _(C))/H _(B)≦2.4  (3)

Moreover, according to still another preferable embodiment of thepresent invention, there are provided a back sheet for solar cellscomprising the above layered product of the present invention, and asolar cell module comprising the back sheet.

Effect of the Invention

The layered product of the present invention comprises the infraredtransmittable colored resin layer (A) layered on one face of theheat-resistant thermoplastic resin layer (B), and the infraredreflective resin layer (C) layered on the other face thereof. Thus, whenlight is applied onto the colored resin layer (A), the colored layer (A)absorbs a visible light and exhibits colored appearance, but transmitsan infrared light to the inside, and the infrared light transmitted fromthe above layer (B) is reflected by the resin layer (C) and againemitted from the above layer (B) and the above layer (A).

Therefore, the infrared reflective layered product of the presentinvention is suitable for uses requiring an infrared reflecting orradiating function such as a back sheet for solar cells, and since it isprevented from heat generation or heat storage caused by the infraredlight and provided with heat resistance, it is suitable for use with anoutdoor device which is exposed to sunlight and a device which radiatesan infrared light.

The infrared reflective layered product of the present invention can beeasily produced because all the three layers can be constituted asmolded resin layers.

The infrared reflective layered product of the present invention doesnot cause curing when the thickness of each layer (A) to (C) satisfiesthe predetermined relation.

When the infrared reflective layered product of the present invention isused as a back sheet for solar cells, infrared light is transmitted fromthe above layer (B) and is reflected by the resin layer (C) and againradiated from the above layer (B) and the above layer (A), and thuspower generation efficiency of solar cells is improved.

When the infrared reflective layered product of the present invention isprovided with the water vapor barrier, it is suitable for use in theoutside exposed to sunlight, wind and rain for a long time, and when itis used as a back sheet for solar cells, it prevents deterioration ofsilicon cells of solar cells.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention is described in detail. In thisspecification, the term “(co)polymer” means homopolymer and copolymer,the term “(meth)acryl” means acryl and/or methacryl, and the term“(meth)acrylate” means acrylate and/or methacrylate.

Base Layer of the Present Invention (Layer (B))

The above layer (B) constituting the base layer of the infraredreflective layered product of the present invention is a thermoplasticresin layer of which a dimensional change (s) satisfies 1%≧s≧−1% whenleft at 150° C. for 30 minutes. The base layer provides durability forlong term use under irradiation of light such as sunlight, andconcurrently has a function of minimizing a dimensional change caused bythermal contraction and thermal expansion even when the present layeredproduct undergoes a dynamic temperature change history during drying orsurface treatment of the layered product after printing or duringanother secondary process. Also, the base layer has a function oftransmitting an infrared radiation transmitted from the above layer (A),and also transmitting the infrared radiation reflected from the abovelayer (C), and the higher the transmittance of the infrared radiationtransmitted from the above layer (A) is, the better the layer (B)becomes. The layer (B) having such a function can be usually produced bymolding a resin without any coloring agent into a film or sheet, and ispreferably transparent or semi-transparent, and more preferabletransparent.

The thermoplastic resin (I) constituting the base layer (hereinafter,also referred to as “Component (I)”) is not particularly limited as longas it satisfies the above dimensional change, but includes vinyl resins(for example, styrene resins, rubber-reinforced styrene resins,acrylonitrile/styrene resins, and aromatic vinyl resins such as(co)polymers of aromatic vinyl compounds), polyolefin resins (forexample, polyethylene resins, polypropylene resins, ethylene-α-olefinresins, and the like), polyvinyl chloride resins, polyvinylidenechloride resins, polyvinyl acetate resins, saturated polyester resins,polycarbonate resins, acrylic resins (for example, (co)polymers of(meth)acrylate compounds), fluorocarbon resins, ethylene/vinyl acetateresins and the like. These can be used alone or in combination of two ormore.

From the viewpoint of heat resistance, the thermoplastic resin (I) has aglass transition temperature of preferably 120° C. or higher, morepreferably 120-220° C., further more preferably 130-190° C., stillfurthermore preferably 140-170° C. and particularly preferably 145-160°C. When the glass transition temperature is less than 120° C., heatresistance is not sufficient.

Examples of the thermoplastic resin (I) typically include a vinyl resin(I′), that is, a rubber-reinforced vinyl resin (I-1) obtained bypolymerization of a vinyl monomer (ii) in the presence of a rubber-likepolymer (i) and/or a (co)polymer (I-2) of a vinyl monomer (ii). Thelatter (co)polymer (I-2) can be obtained by polymerization of the vinylmonomer (ii) in the absence of the rubber-like polymer (i). Therubber-reinforced vinyl resin (I-1) usually includes copolymers in whichthe above vinyl monomer (ii) is graft-copolymerized onto the rubber-likepolymer (i) and an ungrafted component which is made from the vinylmonomer (ii) but is not grafted onto the rubber-like polymer (i) (onewhich is of the same type as the above (co)polymer (I-2)).

Among these, a preferable thermoplastic resin (I) is a rubber-reinforcedstyrene resin (I-1′) obtained by polymerization of a vinyl monomer (ii′)comprising an aromatic vinyl compound and optionally another monomercopolymerizable with the aromatic vinyl compound in the presence of arubber-like polymer (i), and/or a (co)polymer (I-2′) of the vinylmonomer (ii′).

The thermoplastic resin (I) of the present invention preferably containsat least one kind of the rubber-reinforced vinyl resin (I-1) from theviewpoint of impact resistance and flexibility, and may contain the(co)polymer (I-2), if required. The content of the rubber-like polymer(i) is preferably 5-40 parts by mass, more preferably 8-30 parts bymass, furthermore preferably 10-20 parts by mass, and particularlypreferably 12-18 parts by mass relative to 100 parts by mass ofComponent (I). When the content of the rubber-like polymer (i) exceeds40 parts by mass, heat resistance is not sufficient, and processing intoa film may be difficult. On the other hand, when the content of therubber-like polymer (i) is less than 5 parts by mass, impact resistanceand flexibility may be insufficient.

The vinyl resin (I′) preferably comprises, as the vinyl monomer (ii), amaleimide compound unit from the viewpoint of heat resistance. Thecontent of the maleimide compound unit is usually preferably 0-30 mass%, more preferably 1-30 mass %, further more preferably 5-27 mass %,still furthermore preferably 10-27 mass % and particularly preferably15-25 mass % relative to 100 mass % of the thermoplastic resin (I′).When the content of the maleimide compound unit exceeds 30%, flexibilityof the layered product may be insufficient. Also, the maleimide compoundunit may be originated from the rubber-reinforced vinyl resin (I-1) ormay be originated from the (co)polymer (I-2). The glass transitiontemperature of the vinyl resin (I′) can be adjusted by the content ofthe maleimide compound unit as described later, and the (co)polymer(I-2) containing the maleimide compound unit as a constituent monomer isadvantageous for preparing the vinyl resin (I′) having a desired glasstransition temperature.

The above rubber-like polymer (i) includes but is not particularlylimited to conjugated-diene rubbers such as polybutadiene,butadiene/styrene random copolymers, butadiene/styrene block copolymersand butadiene/acrylonitrile copolymers, and the hydrogenated productsthereof (that is, hydrogenated conjugated diene rubbers) as well asnon-diene rubbers such as ethylene-α-olefin rubbers, acrylic rubbers,silicone rubbers and silicone/acrylic composite rubbers, and these canbe used alone or in combination of two or more.

Among these, ethylene-α-olefin rubbers (i-1), hydrogenatedconjugated-diene rubbers (i-2), acrylic rubbers (i-3), silicone rubbers(i-4) and silicone/acrylic composite rubbers (i-5) are preferable fromthe viewpoint of weatherability. Among them, acrylic rubbers (i-3),silicone rubbers (i-4) and silicone/acrylic composite rubbers (i-5) aremore preferable, and silicone/acrylic composite rubbers (i-5) areparticularly preferable from the viewpoint of flexibility. These can beused alone or in combination of two or more.

Examples of ethylene-α-olefin rubbers (i-1) include ethylene/α-olefincopolymers and ethylene/α-olefin/non-conjugated diene copolymers.Examples of the α-olefin constituting the ethylene-α-olefin rubber (i-1)include an α-olefin with 3-20 carbon atoms, and concretely, propylene,1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-heptene, 1-octene,1-decene, 1-dodecene, 1-hexadecene and 1-eicocene. These α-olefins canbe used alone or in combination of two or more. The number of carbonatoms of the α-olefin is preferably 3-20, more preferably 3-12, andfurthermore preferably 3-8. When the number of carbon atoms exceeds 20,copolymerizability is lowered, and surface appearance of molded articlesmay become insufficient. As a typical ethylene-α-olefin rubber (i-1),ethylene/propylene copolymers, ethylene/propylene/non-conjugated dienecopolymers, ethylene/1-butene copolymers andethylene/1-butene/non-conjugated diene copolymers are included. The massratio of ethylene/α-olefin is preferably 5-95/95-5, more preferably50-90/50-10, furthermore preferably 60-88/40-12 and particularlypreferably 70-85/30-15. When the mass ratio of α-olefin exceeds 95,weatherability is not sufficient. On the other hand, when it is lessthan 5, rubber elasticity of the rubber-like polymer is not sufficient,and thus flexibility for a film may be insufficient.

The non-conjugated diene includes alkenyl norbornenes, cyclic dienes andaliphatic dienes, and preferably includes 5-ethylidene-2-norbornene anddicyclopentadiene. These non-conjugated dienes can be used alone or incombination of two or more. The ratio of the non-conjugated diene ispreferably 0-30 mass %, more preferably 0-20 mass % and furthermorepreferably 0-10 mass % relative to the total amount of theethylene-α-olefin rubbers (i-1). When the ratio of the non-conjugateddiene exceeds 30 mass %, appearance of molded articles andweatherability may be insufficient. The amount of unsaturated groups inthe ethylene-α-olefin rubber (i-1) is preferably in a range of 4-40 interms of iodine value.

Mooney viscosity of the ethylene-α-olefin rubber (i-1) (ML₁₊₄, 100° C.;according to JIS K6300) is preferably 5-80, more preferably 10-65 andfurthermore preferably 15-45. When the Mooney viscosity of the Component(i-1) exceeds 80, polymerization may become difficult, and when theMoony viscosity of the Component is less than 5, impact resistance andflexibility for a film may be insufficient.

The hydrogenated conjugated diene rubber (i-2) includes, for example,hydrogenated products of the conjugated diene block copolymer having thefollowing structure. That is, a block copolymer comprising two or moreof a polymer block A composed of an aromatic vinyl compound unit, apolymer block B in which 95 mol % or more of the double bonds of apolymer made from a conjugated diene compound unit with a 1,2-vinyl bondcontent of more than 25 mol % is hydrogenated, a polymer block C inwhich 95 mol % or more of the double bonds of a polymer made from aconjugated diene compound unit with a 1,2-vinyl bond content of not morethan 25 mol % is hydrogenated, and a polymer block D in which 95 mol %or more of the double bonds of a copolymer of an aromatic vinyl compoundunit with a conjugated diene compound unit is hydrogenated.

Examples of aromatic vinyl compounds used for the production of theabove polymer block A include styrene, a-methyl styrene and other methylstyrenes, vinyl xylene, monochlorostyrene, dichlorostyrene,monobromostyrene, dibromostyrene, fluorostyrene, p-t-butylstyrene,ethylstyrene and vinylnaphthalene, and these can be used alone or incombination of two or more. Above all, preferable one is styrene. Theratio of a polymer block A in the block copolymer is preferably 0-65mass % and further preferably 10-40 mass %. When the polymer block Aexceeds 65 mass %, impact resistance may be insufficient.

The above polymer blocks B, C and D can be obtained by hydrogenating apolymer of a conjugated diene compound. The conjugated diene compoundused for the production of the above polymer blocks B, C and D include,for example, 1,3-butadiene, isoprene, 1,3-pentadiene and chloroprene,but in order to obtain the hydrogenated conjugated diene rubbers (i-2)which can be utilized industrially and is excellent in property,1,3-butadiene and isoprene are preferable. These can be used alone or incombination of two or more. The aromatic vinyl compound used for theproduction of the above polymer block D includes the same as thearomatic vinyl compound used for the production of the above polymerblock A, and these can be used alone or in combination of two or more.Above all, preferable one is styrene.

The hydrogenation ratio of the above polymer blocks B, C and D is 95 mol% or more, and preferably 96 mol % or more. When it is less than 95 mol%, gelation occurs during polymerization, and thus polymerization maynot be stably performed. The 1,2-vinyl bond content of the polymer blockB is preferably more than 25 mol % and not more than 90 mol %, andfurther preferably 30-80 mol %. When the 1,2-vinyl bond content of thepolymer block B is not more than 25 mol %, rubbery properties are lostso that impact resistance may be insufficient, and when it exceeds 90mol %, chemical resistance may be insufficient. The 1,2-vinyl bondcontent of the polymer block C is preferably not more than 25 mol %, andfurther preferably not more than 20 mol %. When the 1,2-vinyl bondcontent of the polymer block C exceeds 25 mol %, scratch resistance andsliding properties may not be exhibited sufficiently. The 1,2-vinyl bondcontent of the polymer block D is preferably 25-90 mol %, and furtherpreferably 30-80 mol %. When the 1,2-vinyl bond content of the polymerblock D is less than 25 mol %, rubbery properties are lost so thatimpact resistance may be insufficient, and when it exceeds 90 mol %,chemical resistance may be obtained sufficiently. Also, the content ofthe aromatic vinyl compound of the polymer block D is preferably notmore than 25 mass % and further preferably not more than 20 mass %. Whenthe content of an aromatic vinyl compound of the polymer block D exceeds25 mass %, rubbery properties are lost so that impact resistance may beinsufficient.

The molecular structure of the above block copolymer may be branched,radial or in combination of these, and the block structure thereof maybe diblock, triblock or multiblock or a combination of these. Examplesare block copolymers represented by A-(B-A)_(n), (A-B)_(n), A-(B-C)_(n),C-(B-C)_(n), (B-C)_(n), A-(D-A)_(n), (A-D)_(n), A-(D-C)_(n),C-(D-C)_(n), (D-C)_(n), A-(B-C-D)_(n) or (A-B-C-D)_(n) (where n is aninteger of not less than 1), and preferably a block copolymer having astructure of A-B-A, A-B-A-B, A-B-C, A-D-C or C-B-C.

The weight average molecular weight (Mw) of the above hydrogenatedconjugated diene rubber (i-2) is preferably 10,000-1,000,000, morepreferably 30,000-800,000, and further more preferably 50,000-500,000.When Mw is less than 10,000, flexibility for a film may be insufficient,and on the other hand, when it exceeds 1,000,000, polymerization may bedifficult.

The acrylic rubber (i-3) is a polymer of an alkyl acrylate having analkyl group with 2-8 carbon atoms. Concrete examples of the alkylacrylate include ethyl acrylate, propyl acrylate, n-butyl acrylate,isobutyl acrylate, hexyl acrylate, n-octyl acrylate and 2-ethylhexylacrylate. These can be used alone or in combination of two or more. Apreferable alkyl acrylate is (n-, i)-butyl acrylate or 2-ethylhexylacrylate. A part of the alkyl acrylate can be substituted by anothercopolymerizable monomer in an amount of 20 mass % at maximum. Anothermonomer as above includes, for example, vinylchloride, vinylidenechloride, acrylonitrile, vinylester, alkyl methacrylate, methacrylicacid, acrylic acid and styrene.

It is preferable that kinds and amounts of monomers to be copolymerizedfor the acrylic rubber (i-3) are selected so that it has a glasstransition temperature of not more than −10° C. Also, it is preferableto appropriately copolymerize a crosslinkable monomer in the acrylicrubber, and the amount of the crosslinkable monomer to be used isusually 0-10 mass %, preferably 0.01-10 mass % and further preferably0.1-5 mass % as a proportion relative to the acrylic rubber (i-3).

Concrete examples of the crosslinkable monomer include mono orpolyethylene glycol diacrylates such as ethylene glycol diacrylate,diethylene glycol diacrylate, triethylene glycol diacrylate,tetraethylene glycol diacrylate, mono or polyethylene glycoldimethacrylates such as ethylene glycol dimethacrylate, diethyleneglycol dimethacrylate, triethylene glycol dimethacrylate, tetraethyleneglycol dimethacrylate, di or triallyl compounds such as divinylbenzene,diallylphthalate, diallylmaleate, diallylsuccinate and triallyltriazine,allyl compounds such as allylmethacrylate and allylacrylate, andconjugated diene compounds such as 1,3-butadiene. The above acrylicrubber is produced by known polymerization methods, and a preferablepolymerization method is emulsion polymerization.

As the silicone rubber (i-4), all which can be obtained by knownpolymerization methods can be used, and polyorganosiloxane rubber-likepolymer latex obtained in a form of latex by emulsion polymerization ispreferable from the view point of easiness of graft polymerization.

The latex of the polyorganosiloxane rubber-like polymer can be obtainedby the known method described in, for example, U.S. Pat. Nos. 2,891,920and 3,294,725 specifications. For example, a method in which anorganosiloxane and water are shear-mixed and thencondensation-polymerized in the presence of a sulfonic acid emulsifiersuch as alkylbenzene sulfonic acid and alkylsulfonic acid using ahomomixer or ultrasonic mixer. The alkylbenzene sulfonic acid issuitable because it acts as an emulsifier for the organosiloxane as wellas a polymerization initiator. In this instance, it is preferable to usean alkylbenzene sulfonic acid metal salt or alkylsulfonic acid metalsalt in combination, because they are effective for maintaining polymersto be stable during graft polymerization. If necessary, a grafting agentor crosslinking agent may be condensation-polymerized together to anextent that does not impair the aimed property of the present invention.

The organosiloxane to be used is, for example, one having a structuralunit represented by the general formula R_(m)SiO_((4-m)/2) (wherein R isa substituted or unsubstituted monovalent hydrocarbon group, and mindicates an integer of 0 to 3), and has a linear, branched or cyclicstructure, and is preferably an organosiloxane having a cyclicstructure. The substituted or unsubstituted monovalent hydrocarbon groupof the organosiloxane includes, for example, methyl group, ethyl group,propyl group, phenyl group and these hydrocarbon groups substituted witha cyano group or the like.

Concrete examples of the organosiloxane include cyclic compounds such ashexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane,decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane,trimethyltriphenylcyclotrisiloxane, and a linear or branchedorganosiloxane. These can be used alone or in combination of two ormore.

The organosiloxane may be a polyorganosiloxane that is previouslycondensation-polymerized to have a polystyrene-equivalent weight-averagemolecular weight of, for example, about 500-10,000. Also, when theorganosiloxane is a polyorganosiloxane, a molecular chain terminalthereof may be blocked, for example, by hydroxyl group, alkoxy group,trimethylsilyl group, dimethylvinylsilyl group, methylphenylvinylsilylgroup and methyldiphenylsilyl group.

As the grafting agent, for example, a compound having both unsaturatedgroup and alkoxysilyl group can be used. Concrete examples of such acompound include p-vinylphenylmethyldimethoxysilane,1-(m-vinylphenyl)methyldimethylisopropoxysilane,2-(p-vinylphenyl)ethylmethyldimethoxysilane,3-(p-vinylphenoxy)propylmethyldiethoxysilane,3(p-vinylbenzoyloxy)propylmethyldimethoxysilane,1-(O-vinylphenyl)-1,1,2-trimethyl-2,2-dimethoxydisilane,1-(p-vinylphenyl)-1,1-diphenyl-3-ethyl-3,3-diethoxydisiloxane,m-vinylphenyl-[3-(triethoxysilyl)propyl]diphenylsilane,[3-(p-isopropenylbenzoylamino)propyl]phenyldipropoxysilane,2-(m-vinylphenyl)ethylmethyldimethoxysilane,2-(o-vinylphenyl)ethylmethyldimethoxysilane,1-(p-vinylphenyl)ethylmethyldimethoxysilane,1-(m-vinylphenyl)ethylmethyldimethoxysilane,1-(o-vinylphenyl)ethylmethyldimethoxysilane, and a mixture of these. Ofthese, p-vinylphenylmethyldimethoxysilane,2-(p-vinylphenyl)ethylmethyldimethoxysilane, and3-(p-vinylbenzoyloxy)propylmethyldimethoxysilane are preferable, andp-vinylphenylmethyldimethoxysilane is further preferable.

The ratio of the grafting agent to be used is usually 0-10 parts bymass, preferably 0.2-10 parts by mass and further preferably 0.5-5 partsby mass relative to 100 parts by mass of the total amount of theorganosiloxane, grafting agent and crosslinking agent. When the amountof the grafting agent to be used is too much, the molecular weight ofthe grafted vinyl polymer is lowered, and as a result, sufficient impactresistant cannot be obtained. In addition, oxidative degradation easilyproceeds at double bonds of the grafted polyorganosiloxane rubber-likepolymer, and thus a graft copolymer with good weatherability cannot beobtained.

An average particle diameter of particles of the polyorganosiloxanerubber-like polymer latex is usually not more than 0.5 μm, preferablynot more than 0.4 μm, and further preferably 0.05-0.4 μm. The averageparticle diameter can be easily controlled by amounts of the emulsifierand water, a degree of dispersion upon mixing with the homomixer orultrasonic mixer, or a way of charging the organosiloxane. When theaverage particle diameter of latex particles exceeds 0.5 μm, gloss isinferior.

The polystyrene-equivalent weight-average molecular weight of thepolyorganosiloxane rubber-like polymer obtained as above is usually30,000-1,000,000, and preferably 50,000-300,000. When the weight averagemolecular weight is less than 30,000, flexibility for a film may beinsufficiently. On the other hand, when the weight-average molecularweight exceeds 1,000,000, entanglement within rubber polymer chainsbecomes strong, and rubber elasticity is lowered, and thus flexibilityfor a film is lowered, or graft particles are hardly melted, and filmappearance may be impaired.

The weight-average molecular weight can be easily controlled bytemperature and time of condensation polymerization during preparationof polyorganosiloxane rubber-like polymers. That is, the lower thetemperature of condensation polymerization is and/or the longer thecooling time is, the higher the molecular weight of the polymer is.Also, the polymer can be made high in molecular weight by adding a smallamount of a crosslinking agent.

Meanwhile, the molecular chain terminal of the polyorganosiloxanerubber-like polymer may be blocked, for example, by hydroxyl group,alkoxy group, trimethylsilyl group, dimethylvinylsilyl group,methylphenylvinylsilyl group or methyldiphenylsilyl group.

The amount of the emulsifier to be used is usually 0.1-5 parts by massand preferably 0.3-3 parts by mass relative to 100 parts by mass of thetotal of the organosiloxane, grafting agent and crosslinking agent. Theamount of water to be used in this instance is usually 100-500 parts bymass and preferably 200-400 parts by mass relative to 100 parts by massof the total of the organosiloxane, grafting agent and crosslinkingagent. The condensation polymerization temperature is usually 5-100° C.

During production of the polyorganosiloxane rubber-like polymer, acrosslinking agent can be added as the third component in order toimprove impact resistance of the resulting graft copolymer. Thecrosslinking agent includes, for example, trifunctional crosslinkingagents such as methyl trimethoxysilane, phenyl trimethoxysilane andethyl triethoxysilane, and tetrafunctional crosslinking agents such astetraethoxysilane. These can be used in combination of two or more. Asthese crosslinking agents, crosslinked pre-polymers that are previouslycondensation-polymerized can be used. The addition amount of thecrosslinking agent is usually not more than 10 parts by mass, preferablynot more than 5 parts by mass and further more preferably 0.01-5 partsby mass relative to 100 parts by mass of the total amount of theorganosiloxane, grafting agent and crosslinking agent. When the additionamount of the above crosslinking agent exceeds 10 parts by mass,flexibility of polyorganosiloxane rubber-like polymers may be impairedso that flexibility for a film may be lowered.

The silicone/acrylic composite rubber (i-5) means a rubber-like polymercomprising a polyorganosiloxane rubber and a polyalkyl (meth)acrylaterubber. A preferable silicone/acrylic composite rubber (i-5) is acomposite rubber having a structure in which a polyorganosiloxane rubberand a polyalkyl (meth)acrylate rubber are entangled with each other soas to be inseparable.

The above polyalkyl (meth)acrylate rubber includes, for example, onewhich can be obtained by copolymerizing an alkyl (meth)acrylate(monomer) such as methyl acrylate, ethyl acrylate, n-propyl acrylate,n-butyl acrylate, 2-ethylhexyl acrylate, ethoxyethoxyethyl acrylate,methoxy tripropylene glycol acrylate, 4-hydroxybutyl acrylate, laurylmethacrylate and stearyl methacrylate. These alkyl (meth)acrylates canbe used alone or in combination of two or more.

The above alkyl (meth)acrylate monomer may further comprise variousvinyl monomers including aromatic vinyl compounds such as styrene,a-methyl styrene and vinyl toluene; vinyl cyanide compounds such asacrylonitrile and methacrylonitrile; silicones modified with methacrylicacids; and fluorine-containing vinyl compounds in a range of not morethan 30 mass % as comonomers.

The above polyalkyl (meth)acrylate rubber is preferably a copolymerhaving two or more glass transition temperatures. Such a polyalkyl(meth)acrylate rubber is preferable in order to exhibit flexibility offilms.

As the above polyorganosiloxane rubber, can be used one resulting fromcopolymerization of an organosiloxane. The above organosiloxane includesa variety of reduced products with 3- or more membered ring, andpreferably includes, for example, hexamethylcyclotrisiloxane,octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane,dodecamethylcyclohexasiloxane, trimethyltriphenylcyclotrisiloxane,tetramethyltetraphenylcyclotetrasiloxane andoctaphenylcyclotetrasiloxane. These organosiloxanes can be used alone orin combination of two or more. The amount of these organosiloxanes to beused is preferably not less than 50 mass %, and more preferably not lessthan 70 mass % relative to the polyorganosiloxane rubber components.

A silicone/acrylic composite rubber (i-5) can be produced, for example,by methods described in such as JP-A-H04-239010 and JP-B-2137934. Assuch a silicone/acrylic composite rubber graft copolymer, “METABLENESX-006 (trade name)” manufactured by MITSUBISHI RAYON CO., LTD. iscommercially available.

The vinyl monomer (ii) in the present invention typically includesaromatic vinyl compounds and vinyl cyanide compounds, and is preferablyone comprising both an aromatic vinyl compound and a vinyl cyanidecompound.

The aromatic vinyl compounds include, for example, styrene, α-methylstyrene and other methyl styrene, vinyl toluene, vinyl xylene, ethylstyrene, dimethyl styrene, p-tert-butyl styrene, vinyl naphthalene,methoxy styrene, monobromo styrene, dibromo styrene, tribromo styreneand fluorostyrene. Of these, styrene and a-methyl styrene arepreferable. These aromatic vinyl compounds can be used alone or incombination of two or more.

The vinyl cyanide compounds include acrylonitrile, methacrylonitrile andα-chloro(meth)acrylonitrile. Of these, acrylonitrile is preferable.These vinyl cyanide compounds can be used alone or in combination of twoor more.

As the vinyl monomer (ii), can be used, in addition to the aromaticvinyl compound and the vinyl cyanide compound, another compoundcopolymerizable with these. Such another compound includes(meth)acrylates, maleimide compounds, other functional group-containingunsaturated compounds (for example, unsaturated acids, epoxygroup-containing unsaturated compounds, hydroxyl group-containingunsaturated compounds, oxazoline group-containing unsaturated compoundsand acid anhydride group-containing unsaturated compounds). These can beused alone or in combination of two or more. The amount of such anothercompound to be used is preferably 0-50 mass %, more preferably 1-40 mass% and further more preferably 1-30 mass %, provided that the vinylmonomer (ii) is 100 mass %.

The (meth)acrylate includes, for example, methyl (meth)acrylate, ethyl(meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate,n-butyl (meth)acrylate and isobutyl (meth)acrylate. These can be usedalone or in combination of two or more. Of these, methyl methacrylate ispreferable.

The unsaturated acid includes, for example, acrylic acid, methacrylicacid, itaconic acid and maleic acid. These can be used alone or incombination of two or more.

The maleimide compound includes, for example, maleimide,N-methylmaleimide, N-butylmaleimide, N-phenylmaleimide andN-cyclohexylmaleimide. These can be used alone or in combination of twomore. In order to introduce a maleimide compound unit into acopolymerized resin, maleic anhydride may be first (co)polymerized,followed by imidation. Containing a maleimide compound as anothercopolymerizable compound is preferable from the viewpoint of improvingheat resistance of the thermoplastic resin (I).

The content of the maleimide compound is usually preferably 0-30 mass %,more preferably 1-30 mass %, further more preferably 5-27 mass %, stillfurthermore preferably 10-27 mass % and particularly preferably 15-25mass % as the maleimide compound unit relative to 100 mass % of theabove thermoplastic resin (I). When the maleimide compound unit is lessthan 1 mass %, heat resistance may be insufficient. On the other hand,when it exceeds 30 mass %, flexibility for a film may be insufficient.

The epoxy group-containing unsaturated compound includes, for example,glycidyl acrylate, glycidyl methacrylate and allyl glycidyl ether, andthese can be used alone or in combination of two or more.

The hydroxyl group-containing unsaturated compound includes, forexample, 3-hydroxy-1-propene, 4-hydroxy-1-butene,cis-4-hydroxy-2-butene, trans-4-hydroxy-2-butene,3-hydroxy-2-methyl-1-propene, 2-hydroxyethyl acrylate, 2-hydroxyethylmethacrylate and hydroxystyrene. These can be used alone or incombination of two or more.

The oxazoline group-containing unsaturated compound includes, forexample, vinyl oxazolines. These can be used alone or in combination oftwo or more.

The acid anhydride group-containing unsaturated compound includes, forexample, maleic anhydride, itaconic anhydride and citraconic anhydride.These can be used alone or in combination of two or more.

As the above vinyl monomer (ii), one which is mainly composed of anaromatic vinyl compound and a vinyl cyanide compound is preferable, andthe total amount of these compounds is preferably 70-100 mass % andfurther preferably 80-100 mass % relative to the total amount of thevinyl monomer. The ratio of an aromatic vinyl compound and an vinylcyanide compound to be used is preferably 5-95 mass % and 5-95 mass %,more preferably 50-95 mass % and 5-50 mass %, further more preferably60-95 mass % and 5-40 mass % and particularly preferably 65-85 mass %and 15-35 mass % respectively, provided that the total of these is 100mass %.

According to a preferable embodiment of the present invention, as thethermoplastic resin (I), is used a rubber-reinforced styrene resin whichcomprises a rubber-reinforced styrene resin (I-1′) obtained bypolymerization of a vinyl monomer (ii′) containing an aromatic vinylcompound in the presence of a rubber-like polymer (i) selected from thegroup consisting of acrylic rubbers (i-3), silicone rubbers (i-4) andsilicone/acrylic composite rubbers (i-5) and optionally a (co)polymer(I-2′) of a vinyl monomer (ii). Of these, preferable are asilicone/acrylic composite rubber-reinforced styrene resin using asilicone/acrylic composite rubber (i-5) as the rubber-like polymer (i),and a mixture of a silicone rubber-reinforced styrene resin using asilicone rubber (i-4) as the rubber-like polymer (i) and an acrylicrubber-reinforced styrene resin using an acrylic rubber (i-3) as therubber-like polymer (i), and particularly preferable is thesilicone/acrylic composite rubber-reinforced styrene resin.

The rubber-reinforced vinyl resin (I-1) can be obtained by knownpolymerization methods such as emulsion polymerization, suspensionpolymerization, solution polymerization, bulk polymerization andpolymerization methods in combination of these.

The graft ratio of the rubber-reinforced vinyl resin (I-1) is preferably20-170%, more preferably 30-170%, further more preferably 40-150% andparticularly preferably 50-150%. When the graft ratio is too low,flexibility for a film may be insufficient. When it is too high,viscosity of the thermoplastic resin becomes high so that a thin productmay be difficult to make.

The graft ratio can be determined by the following equation.

Graft ratio(mass %)={(S−T)/T}×100

In the above equation, S is the mass (g) of insoluble matter obtained byadding 1 g of the rubber-reinforced vinyl resin (I-1) into 20 ml ofacetone (but acetonitrile when an acrylic rubber is used), shaking themixture for 2 hours by a shaker under the temperature of 25° C., andthen centrifuging the mixture by a centrifuge (at a rotation speed of23,000 rpm) for 60 minutes under the temperature of 5° C. to separatethe insoluble matter from soluble matter, and T is the mass (g) of therubber-like polymer contained in 1 g of the rubber-reinforced vinylresin (I-1). The mass of the rubber-like polymer can be obtained by amethod of calculating based on polymerization prescription andpolymerization conversion, a method of determining from infraredabsorption spectrum (IR) and the like.

Meanwhile, the graft ratio can be adjusted by appropriately selecting,for example, kind and amount of a chain transfer agent used in theproduction of the rubber-reinforced vinyl resin (I-1), kind and amountof a polymerization initiator, method of addition and duration ofaddition of monomer components during polymerization, and polymerizationtemperature.

The limiting viscosity [η] (measured at 30° C. in methyl ethyl ketone)of the soluble matter in acetone (but acetonitrile when acrylic rubberis used) of the rubber-reinforced resin (I-1) is preferably 0.1 to 2.5dl/g, more preferably 0.2 to 1.5 dl/g, and further more preferably 0.25to 1.2 dl/g. It is preferable that the limiting viscosity is within thisrange from the viewpoint of processability of a film and thicknessaccuracy of layered products.

The limiting viscosity [η] of the soluble matter in acetone (butacetonitrile when acrylic rubber is used) of the rubber-reinforced resin(I-1) is measured by the following method. First, the soluble matter inacetone (but acetonitrile when acrylic rubber is used) of therubber-reinforced resin (I-1) is dissolved in methyl ethyl ketone tomake five samples different in concentration. Then, the limitingviscosity [η] is obtained from the results of a reduced viscositymeasured at each concentration at 30° C. using the Ubbelohde viscometertube. The unit is dl/g.

The limiting viscosity [η] can be adjusted by appropriately selecting,for example, kind and amount of a chain transfer agent used in theproduction of the rubber-reinforced vinyl resin (I-1), kind and amountof a polymerization initiator, method of addition and duration ofaddition of monomer components during polymerization, and polymerizationtemperature. Also, it can be adjusted by appropriately selecting andblending (co)polymers (I-2) different in limiting viscosity [η].

The thermoplastic resin (I) may be pelletized by previously blendingrequired amounts of the respective components, mixing the blend in aHenschel mixer or the like, and then melt-kneading it in an extruder, ormay be processed into a film or sheet by directly supplying therespective components to a film forming machine or extruding machine. Inthis instance, antioxidants, ultraviolet absorbents, weather resistantagents, anti-aging agents, fillers, antistatic agents, flame retardants,antifogging agents, slipping agents, antibacterial agents, fungicides,tackifiers, plasticizers, coloring agents, graphite, carbon black,carbon nanotube, and pigments (including a pigment to whichfunctionality such as an infrared absorbing or reflecting property isimparted) can be added to the thermoplastic resin (I) in an amount whichdoes not impair the object of the present invention.

Colored Resin Layer of the Present Invention (Layer (A))

The layer (A) of the present invention is an infrared transmittablecolored resin layer, and concretely a colored resin layer having anabsorptance of a light with a wavelength of 800-1400 nm of not more than10%. The layer (A) can be constituted, for example, by containing acoloring agent, especially an infrared transmittable coloring agent in aresin component that constitutes the layer (A).

In the present invention, the absorptance of a light with a wavelengthof 800-1400 nm of not more than 10% means that a minimum value ofabsorptance within a wavelength range of 800-1400 nm is not more than10%, but does not require that the absorptance of the entire lightwithin the wavelength range of 800-1400 nm is 10% or less. Normally,when the absorptance of a light at one wavelength of the wavelengthrange of 800-1400 nm is not more than 10%, it is considered that theabsorptance of a light with a wavelength adjacent to it is also loweredto the same extent.

The infrared transmittable coloring agent has a property of absorbing avisible light to effect coloration and transmitting infrared radiation,and concrete examples include perylene black pigments. Such peryleneblack pigments are commercially available as “Paliogen Black 50084,Paliogen Black L0086, Lumogen Black FK4280 and Limogen Black FK4281(trade name: manufactured by BASF)”. Also, as the infrared transmittablecoloring agent, perylene pigments described in JP-A-2007-128943 can beused. Such an infrared transmittable coloring agent can be used alone orin combination of two or more.

In addition, the infrared transmittable coloring agent can be used incombination with other coloring agents such as pigments and dyes as longas it does not impair infrared transmittability of the layer (A). Asother coloring agents, known inorganic pigments, organic pigments anddyes can be used. For example, when a yellow pigment is used incombination with a perylene black pigment, a brown layer (A) can beobtained, and when a blue pigment is used in combination, a dark bluelayer (A) can be obtained, and when a white pigment is used incombination, a grey layer (A) can be obtained.

Degree of coloring of the layer (A) is not particularly limited as longas it satisfies the infrared transmittability of the layer (A), butusually it only has to be colored to make the L value (brightness) of asurface on the layer (A) side of a layered product to be not more than40, preferably not more than 35 and more preferably not more than 30.Meanwhile, a surface on the layer (A) side of the layered product meansa surface of the layer (A) when none of a water vapor barrier layer (D)and a protective layer (E) is provided on the outer surface of the layer(A), a surface of the layer (D) when the water vapor barrier layer (D)is provided on the outer surface of the layer (A), and a surface of theprotective layer (E) when the protective layer (E) is provided on asurface on the layer (A) side.

The content of the coloring agent (the total amount of the infraredtransmittable coloring agent and other coloring agents) in the layer (A)is not particularly limited as long as it does not impair infrared raytransmittability of the layer (A), but usually 0.1-5 parts by mass ispreferable, 0.1-4.5 parts by mass is more preferable, and 0.5-4.0 partsby mass is further more preferable. When the content of the coloringagent is less than 0.1 parts by mass, coloring may be insufficient, andwhen the content of the coloring agent exceeds 5 parts by mass,transmittability of infrared radiation may be insufficient andproduction cost may be increased.

A resin component constituting the layer (A) is not particularlylimited, but from the viewpoint of molding processability of the layeredproduct, a thermoplastic resin (II) is preferable. Also, thethermoplastic resin (II) preferably has a glass transition temperaturelower than that of a thermoplastic resin (I) constituting the abovelayer (B), from a point of imparting flexibility to the layered product.The thermoplastic resin (II) preferably has the glass transitiontemperature of 90-200° C., more preferably 95-160° C., further morepreferably 95-150° C. and particularly preferably 110-140° C. When thethermoplastic resin (II) has the glass transition temperature of higherthan 200° C., flexibility of the layered product tends to bedeteriorated, and on the other hand, when it is lower than 90° C., heatresistance tends to be insufficient.

Examples of the thermoplastic resin (II) include styrene resins (forexample, rubber-reinforced styrene resins, acrylonotrile/styrene resins,other (co)polymers of aromatic vinyl compounds, and the like),polyolefin resins (for example, polyethylene resins, polypropyleneresins, ethylene-α-olefin resins, and the like), polyvinyl chlorideresins, polyvinylidene chloride resins, polyvinyl acetate resins,saturated polyester resins (for example, polyethylene terephthalate,polybutylene terephthalate, polyethylene naphthalate, polytrimethyleneterephthalate, and the like), polycarbonate resins, acrylic resins (forexample, (co)polymers of (meth)acrylate compounds), fluorocarbon resins,ethylene/vinyl acetate resins and the like. These can be used alone orin combination of two or more. Of these, from the viewpoint ofdifficulty in hydrolysis even used outside for a long time, use ofstyrene resin (II-1) is preferable.

The styrene resin (II-1) used in the present invention (hereinafter alsoreferred to as “Component (II-1)”) is typically a rubber-reinforcedstyrene resin composition (II-1-1) obtained by polymerization of a vinylmonomer (b) comprising an aromatic vinyl compound and optionally anothermonomer copolymerizable with the aromatic vinyl compound in the presenceof a rubber-like polymer (a) and/or a (co)polymer (II-1-2) of a vinylmonomer (b). The latter (co)polymer (II-1-2) can be obtained bypolymerization of a vinyl monomer (b) in the absence of the rubber-likepolymer (a). The rubber-reinforced styrene resin (II-1-1) usuallyincludes copolymers in which the above vinyl monomer (b) isgraft-copolymerized onto the rubber-like polymer (a) and an ungraftedcomponent which is made from the vinyl monomer (b) but is not graftedonto the rubber-like polymer (a) (one which is of the same type as theabove (co)polymer (II-1-2)).

The Component (II-1) of the present invention preferably contains atleast one kind of the rubber-reinforced styrene resin (II-1-1) from theviewpoint of impact resistance and flexibility, and may contain the(co)polymer (II-1-2), if required. The content of the rubber-likepolymer (a) is preferably 5-40 parts by mass, more preferably 8-30 partsby mass, furthermore preferably 10-20 parts by mass, and particularlypreferably 12-18 parts by mass relative to 100 parts by mass ofComponent (II-1). When the content of the rubber-like polymer (a)exceeds 40 parts by mass, heat resistance is not sufficient, andprocessing into a film may be difficult. On the other hand, when thecontent of the rubber-like polymer (a) is less than 5 parts by mass,flexibility may be insufficient.

As the rubber-like polymer (a), can be used one described above as therubber-like polymer (i), and the preferable rubber-like polymer (a) isthe same as the rubber-like polymer (i). However, in the layered productof the present invention, the rubber-like polymer (a) used in thestyrene resin (II-1) may be the same as or different from therubber-like polymer (i) used in the thermoplastic resin (I).

As the vinyl monomer (b), can be used one described above as the vinylmonomer (ii), and the preferable vinyl monomer (b) is the same as thevinyl monomer (ii). However, in the layered product of the presentinvention, the vinyl monomer (b) used in the styrene resin (II-1) may bethe same as or different from the vinyl monomer (ii) used in thethermoplastic resin (I).

The styrene resin (II-1) preferably comprises a maleimide compound unitfrom the viewpoint of heat resistance. The content of the maleimidecompound unit is usually preferably 0-30 mass %, more preferably 1-30mass %, furthermore preferably 5-25 mass % and particularly preferably10-20 mass % relative to 100 mass % of the styrene resin (II-1). Also,the maleimide compound unit may be originated from the rubber-reinforcedstyrene resin (II-1-1) or may be originated from the (co)polymer(II-1-2). The glass transition temperature of the styrene resin (II-1)can be adjusted by the content of the maleimide compound unit asdescribed later, and the (co)polymer (II-1-2) containing the maleimidecompound unit as a constituent monomer is advantageous for preparing astyrene resin (II-1) having a desired glass transition temperature.

According to a preferable embodiment of the present invention, as thethermoplastic resin (II), is used a rubber-reinforced styrene resinwhich comprises a rubber-reinforced styrene resin (II-1-1) obtained bypolymerization of a vinyl monomer (b) comprising an aromatic vinylcompound in the presence of a rubber-like polymer (a) selected from thegroup consisting of acrylic rubbers (i-3), silicone rubbers (i-4) andsilicone/acrylic composite rubbers (i-5) and optionally a (co)polymer(II-1-2) of a vinyl monomer (b). Of these, preferable are asilicone/acrylic composite rubber-reinforced styrene resin using asilicone/acrylic composite rubber (i-5) as the rubber-like polymer (b),and a mixture of a silicone rubber-reinforced styrene resin using asilicone rubber (i-4) as the rubber-like polymer (b) and an acrylicrubber-reinforced styrene resin using an acrylic rubber (i-3) as therubber-like polymer (b), and particularly preferable is thesilicone/acrylic composite rubber-reinforced styrene resin.

The styrene resin (II-1) can be obtained by known polymerization methodssuch as emulsion polymerization method, suspension polymerization,solution polymerization, bulk polymerization and polymerization methodsin combination of these.

The graft ratio of the rubber-reinforced styrene resin (II-1-1) ispreferably 20-170%, more preferably 30-170°, furthermore preferably40-150% and particularly preferably 50-150%. When the graft ratio is toolow, flexibility for a film may be insufficient. When the graft ratio istoo high, viscosity of the thermoplastic resin becomes high so that athin product may be difficult to make.

The graft ratio can be measured by the same method as mentioned aboutthe rubber-reinforced vinyl resin (1-1).

Meanwhile, the graft ratio can be adjusted by appropriately selecting,for example, kind and amount of a chain transfer agent used in theproduction of the rubber-reinforced styrene resin (II-1-1), kind andamount of a polymerization initiator, method of addition and duration ofaddition of monomer components during polymerization, and polymerizationtemperature.

The limiting viscosity [η] (measured at 30° C. in methyl ethyl ketone)of the soluble matter in acetone (but acetonitrile when acrylic rubberis used) of the rubber-reinforced styrene resin (II-1-1) is preferably0.1 to 2.5 dl/g, more preferably 0.2 to 1.5 dl/g, and furthermorepreferably 0.25 to 1.2 dl/g. It is preferable that the limitingviscosity is within this range from the viewpoint of thickness accuracyof layered products.

The limiting viscosity [η] can be measured in the same manner as therubber-reinforced vinyl resin (I-1).

The limiting viscosity [η] can be adjusted by appropriately selecting,for example, kind and amount of a chain transfer agent used in theproduction of the rubber-reinforced styrene resin (II-1-1), kind andamount of a polymerization initiator, method of addition and duration ofaddition of monomer components during polymerization, and polymerizationtemperature. Also, it can be adjusted by appropriately selecting andblending (co)polymers (II-1-2) different in limiting viscosity [η].

The styrene resin (II-1) may be pelletized by previously blendingrequired amounts of the respective components, mixing the blend in aHenschel mixer or the like, and then melt-kneading it in an extruder, ormay be processed into a film or sheet by directly supplying therespective components to a film forming machine or extruding machine. Inthis instance, antioxidants, ultraviolet absorbents, weather resistantagents, anti-aging agents, fillers, antistatic agents, flame retardants,antifogging agents, slipping agents, antibacterial agents, fungicides,tackifiers, plasticizers, coloring agents, graphite, carbon black,carbon nanotube, and the like can be added to the styrene resin (II-1)in an amount which does not impair the object of the present invention.

Colored Resin Layer of the Present Invention (Layer (C))

The layer (C) of the present invention is a light reflective coloredresin layer, and concretely has a reflectance of a light with awavelength of 400-1400 nm of not less than 50%, preferably not less than60% and particularly preferably not less than 70%. The layer (C) can beconstituted by molding a resin which is obtained by mixing a coloringagent with high brightness in a resin component constituting the layer(C). Therefore, degree of coloring of the layer (C) is not particularlylimited as long as it satisfies the above reflectance, but usually it iscolored so that the surface on the layer (C) side of the layered producthas an L value (brightness) of about not less than 55, preferably notless than 70, more preferably not less than 80 and particularlypreferably not less than 95. Meanwhile, the surface on the layer (C)side of the layered product means the surface of the layer (C) when nowater vapor barrier layer (D) is provided on the outer surface of thelayer (C), and the surface of the layer (D) when the water vapor barrierlayer (D) is provided on the outer surface of the layer (C), regardlessof a protective layer (E). One with a white front or back face isconventionally known for use as a back sheet for solar cells, but thepresent invention has made a layer with high brightness function as areflective layer against an infrared radiation transmitted from thecolored resin layer (A).

In the present invention, the reflectance of a light with a wavelengthof 400-1400 nm of not less than 50% means that a maximum value ofreflectance within a wavelength of 400-1400 nm is not less than 50%, anddoes not require that the reflectance of the entire light within thewavelength of 400-1400 nm is 50% or more. Normally, when the reflectanceof a light at one wavelength of the wavelength range of 400-1400 nm isnot less than 50%, it is considered that the reflectance of a light witha wavelength adjacent to it is also enhanced to the same extent. Sincethe layer (C) has a function of reflecting an infrared radiation whichhas been transmitted from the layer (A) and layer (B), it has areflectance of a light with a wavelength of 800-1400 nm of preferablynot less than 50%, that is, it is preferable that the maximum value ofreflectance within a wavelength of 800-1400 nm is not less than 50%.

The coloring agent with high brightness which is blended in the abovelayer (C) is not particularly limited as long as it has a property ofreflecting an infrared radiation, and usually white pigments are used.Examples of the white pigment include ZnO, TiO₂, Al₂O₃.nH₂O,[ZnS+BaSO₄], CaSO₄.2H₂O, BaSO₄, CaCO₃ and 2PbCO₃.Pb(OH)₂. These can beused alone or in combination of two or more.

The content of a pigment in the layer (C) is not particularly limited aslong as it does not impair infrared reflectivity of the layer (C), butit is preferably an amount sufficient to make the L value (brightness)of a surface on the layer (C) side of the layered product to be not lessthan 55, and concretely it is preferably 1-40 parts by mass, morepreferably 3-40 parts by mass, furthermore preferably 5-30 parts by massand particularly preferably 10-25 parts by mass relative to 100 parts ofthe resin components constituting the layer (C). When the content isless than 1 part by mass, effect of infrared reflection is notsufficient, and when it exceeds 40 parts by mass, flexibility for a filmmay be insufficient.

As the resin component constituting the layer (C), can be used onedescribed above about the layer (A), and a thermoplastic resin (II) ispreferable from the viewpoint of molding processability of layeredproducts. Also, the thermoplastic resin (II) preferably has a lowerglass transition temperature than the thermoplastic resin (I)constituting the layer (B), from the viewpoint of imparting flexibilityto the layered product. The glass transition temperature of thethermoplastic resin (II) is preferably 90-200° C., more preferably95-160° C., furthermore preferably 95-150° C. and particularlypreferably 110-140° C. When the glass transition temperature of thethermoplastic resin (II) is higher than 200° C., flexibility of thelayered product may be deteriorated, and on the other hand, when theglass transition temperature is lower than 90° C., heat resistance maytend to be insufficient. Meanwhile, all description includingdescription of the preferable thermoplastic resin (II) described aboveabout the layer (A) is also applied to a resin component constitutingthe layer (C) as it is.

According to a preferable embodiment of the present invention, as thethermoplastic resin (II) constituting the layer (C), is used arubber-reinforced styrene resin which comprises a rubber-reinforcedstyrene resin (II-1-1) obtained by polymerization of a vinyl monomer (b)comprising an aromatic vinyl compound in the presence of a rubber-likepolymer (a) selected from the group consisting of acrylic rubbers (i-3),silicone rubbers (i-4) and silicone/acrylic composite rubbers (i-5) andoptionally a (co)polymer (II-1-2) of a vinyl monomer (b). Of these,preferable are a silicone/acrylic composite rubber-reinforced styreneresin using a silicone/acrylic composite rubber (i-5) as the rubber-likepolymer (b), and a mixture of a silicone rubber-reinforced styrene resinusing a silicone rubber (i-4) as the rubber-like polymer (b) and anacrylic rubber-reinforced styrene resin using an acrylic rubber (i-3) asthe rubber-like polymer (b), and particularly preferable is thesilicone/acrylic composite rubber-reinforced styrene resin.

Water Vapor Barrier Layer of the Present Invention (Layer (D))

In the layered product of the present invention, a water barrier layer(D) can be optionally layered on an outer surface of the above layer (A)or the above layer (C), or between the above layer (A) and the abovelayer (B) or the above layer (B) and the above layer (C).

Of these, the water vapor barrier layer (D) is preferably layered on anouter surface of the above layer (A) or the above layer (C). From theviewpoint of water vapor barrier property, the water vapor barrier layer(D) is preferably layered on the outer surface of the above layer (A),and from the viewpoint of adhesion to solar cells, the water vaporbarrier layer (D) is preferably layered to the outer surface of theabove layer (C).

The water vapor barrier layer has an effect of preventing water vaporfrom permeating the layered product of the present invention, and it isnot particularly limited as long as it has this effect, but when it isprovided on the outer surface of the above layer (A), or between theabove layer (A) and the above layer (B) or the above layer (B) and theabove layer (C), it is required to have infrared transmittability likethe layer (B).

The total light transmittance of the water vapor barrier layer ispreferably not less than 70%, more preferably not less than 80% andfurthermore preferably not less than 85%. Also, haze of the water vaporbarrier layer is preferably not more than 10%, more preferably not morethan 7% and furthermore preferably not more than 5%. The total lighttransmittance and haze are measured in accordance with JIS K 7136 or JISK 7105. The moisture permeability of the water vapor barrier layer (alsoreferred to as water vapor permeability) as measured under a conditionat a temperature of 40° C. and humidity of 90% R.H. in accordance withJIS K 7129, is preferably 3 g/m²·d or lower, more preferably 1 g/m²·d orlower, and further more preferably 0.7 g/m²·d or lower.

As the water vapor barrier layer, usually a thin film layer made ofmetals and/or metal oxides can be used. Examples of the metal includealuminum, and examples of the metal oxide include silicone oxide and/oraluminum oxide. The thin film layer may be formed by metal-plating orvapor-depositing the above metal or metal oxide to the above layer (A),(B) or (C).

In addition, the water vapor barrier layer can be formed by using awater vapor barrier film which comprises the above thin film layer whichis previously vapor-deposited in a synthetic resin film. From theviewpoint of cost, it is preferable to use the water vapor barrier filmwhich comprises the above thin film layer vapor-deposited on a syntheticresin film with a thickness of preferably about 5-50 μm and morepreferably 10-15 μm. As such a resin film, generally can be used onewhich is molded from a synthetic resin without any coloring agent into afilm or sheet, and it is preferably transparent or semi-transparent andmore preferably transparent. As such a synthetic resin, generallypolyethylene terephthalate (PET) film can be used. As such a water vaporbarrier film, commercially available one can be used, and for example,“TECHBARRIER AX (trade name)” manufactured by MITSUBISHI PLASTICS, INC.,“GX film (trade name)” manufactured by TOPPAN PRINTING CO., LTD. and“ECOSYAR VE500 (trade name)” manufactured by Toyobo Co., Ltd.

The water vapor barrier film may be layered on the outer surface of thelayer (A) or layer (C) after the layered product with three layers ofthe layers (A), (B) and (C) is obtained, or may be previously layered onthe layer (A), (B) or (C) before the layered product is obtained, or maybe layered at the same time as the layers (A), (B) and (C). Thelaminating method may be a method in which lamination is performed inaccordance with dry laminating method using an adhesive agent, or amethod in which lamination is performed without any adhesive agent bycoextrusion at the same time when at least one of the layers (A), (B)and (C) is molded, or at the same time when the layers (A), (B) and (C)are molded. As the above adhesive agent, polyurethane adhesive agents,epoxy adhesive agents and acrylic adhesive agents can be used, and ofthese, polyurethane adhesive agents are preferably used.

It is preferable that the back sheet for solar cells of the presentinvention shows a water vapor permeability of 3 g/m²·d or lower asmeasured in the water vapor permeability test in accordance with JIS K7129B at a temperature of 40° C. and humidity of 90% RH. When the watervapor permeability is higher than 3 g/m²·d, durability of solar cellsmay be impaired.

Structure of the Layered Product

The infrared reflective layered product of the present invention can beproduced by providing the layer (B) as a base layer, laminating theinfrared transmittable colored resin layer (A) onto one face of thelayer (B), and laminating the infrared reflective colored resin layer(C) onto the other face.

When the layered product of the present invention comprises the watervapor barrier layer (D), the layered product has a structure in whichthe layer (B) is provided as a base layer, and the infraredtransmittable colored resin (A) is arranged on one side of the layer(B), and the infrared ray reflective colored resin (C) is arranged onthe other side of the layer (B), and the water vapor barrier layer (D)is arranged on the outer surface of the layer (A) or layer (C), orbetween the layer (A) and the layer (B) or the layer (B) and the layer(C). Of these, from the viewpoint of easiness of production, the watervapor barrier layer (D) is preferably provided on the outer surface ofthe above layer (A) or the above layer (C). As shown in FIG. 1, when acommercially available water vapor barrier film D comprising a syntheticresin film D1 and a thin film layer D2 of a metal and/or metal oxidelayered thereon is used, such a commercially available water vaporbarrier film D is generally inferior in weatherability, and thus it ispreferably layered on the outer surface of the above layer (A). Sincethe layer (A) is arranged on the silicone cell S side of solar cells,the layer (D) is protected by the layers (A) to (C), and thus thisarrangement is advantageous. When the synthetic resin film D1 is made ofa material inferior in hydrolytic resistance like a polyethyleneterephthalate (PET) film, it is preferable that the layer (D) is layeredso that the thin film layer D2 faces the above layer (A) as shown inFIG. 1. This arrangement is advantageous in that the synthetic resinfilm D1 is protected by the thin film layer D2 from invasion of moisturefrom the outside. Meanwhile, in FIG. 1, S denotes the silicon cell forsolar cells, A denotes the layer (A), B denotes the layer (B), C denotesthe layer (C), D denotes the layer (D), D1 denotes the synthetic resinfilm and D2 denotes the thin film layer.

According to a preferable embodiment of the infrared reflective layeredproduct of the present invention, in order to impart heat resistance andflexibility to the layered product as mentioned above, the layer (B) isconstituted by a thermoplastic resin (I) with a glass transitiontemperature of not less than 120° C., and the layer (A) and the layer(C) are constituted by a thermoplastic resin (II) with a glasstransition temperature lower than the thermoplastic resin (I). It isadvantageous that the thermoplastic resin (II) constituting the layer(A) is the same as that of the layer (C) except the pigment to beblended. The glass transition temperature (Tg (I)) of the thermoplasticresin (I) of the layer (B) and the glass transition temperature (Tg(II)) of the thermoplastic resin (II) of the layer (A) and the layer (C)preferably satisfy the following expression (1):

(Tg(I)−Tg(II))≧10° C.  (1),

more preferably the following expression (1′):

50° C.≧(Tg(I)−Tg(II))≧10° C.  (1′),

and furthermore preferably the following expression (1″):

30° C.≧(Tg(I)−Tg(II))≧15° C.  (1″).

When the glass transition temperatures of the thermoplastic resin (I)and the thermoplastic resin (II) do not satisfy the expression (1),improvement in effect of flexibility of the resulting layered productmay be insufficient. When a difference between the glass transitiontemperature (Tg (I)) of the thermoplastic resin (I) and the glasstransition temperature (Tg (II)) of the thermoplastic resin (II) exceed50° C., the layered product tends to be difficult to produce.

The glass transition temperatures of the thermoplastic resin (I)(especially vinyl resin (I′)) and the styrene resin (II-1) can beadjusted by appropriately selecting kind or amount of the rubber-likepolymer (i) or (a) to be used, or kind or amount of the vinyl monomer(ii) or (b) to be used, and suitably by changing an amount of themaleimide compound. Also, the glass transition temperature can beadjusted by blending an additive or filler such as a plasticizer and aninorganic filler.

In the layered product of the present invention, both of thethermoplastic resin (I) of a layer (B) and the thermoplastic resin (II)of a layer (A) and layer (C) are preferably resin compositions whichcomprise a silicone/acrylic composite rubber-reinforced styrene resinobtained by polymerization of a vinyl monomer (ii), (a) in the presenceof a silicone/acrylic composite rubber (i-5) and contain a maleimidecompound unit, from the viewpoint of balance of weatherability, heatresistance, hydrolytic resistance and flexibility. In this case, fromthe viewpoint of balance of weatherability, heat resistance, hydrolyticresistance and flexibility, it is preferable that the silicone/acryliccomposite rubber-reinforced styrene resin constituting the thermoplasticresin (I) of a layer (B) contains the rubber in an amount of 10-20 partsby mass relative to 100 parts by mass of the thermoplastic resin (I),and has a glass transition temperature of 150-160° C. with the contentof N-phenyl maleimide unit being 15-30 mass % relative to 100 mass % ofthe thermoplastic resin (I) whilst the silicone/acrylic compositerubber-reinforced styrene resin constituting the thermoplastic resin(II) of a layer (A) and a layer (C) contains the rubber in an amount of10-20 parts by mass relative to 100 parts by mass of the thermoplasticresin (II), and has a glass transition temperature of 120-140° C. withthe content of N-phenyl maleimide unit being 10-20 mass % relative to100 mass % of the thermoplastic resin (II).

The layered product of the present invention may be in a form of eithersheet or film. For example, when the layered product of the presentinvention is a film, it can be produced by methods which can be utilizedfor producing a film of a thermoplastic resin, including, for example,solution cast method, melt extrusion method, coextrusion method and meltpress method. The melt extrusion method is excellent for a large scaleproduction, but the solution cast method and melt press method are alsouseful for the purpose of a small scale or special application orquality evaluation. In the melt extrusion method, T-die or inflationmethod is used. In the melt press method, calendar method is used. Whenthe layered product of the present invention is a sheet, it can beproduced by methods which can be utilized for producing a thermoplasticsheet, including, for example, coextrusion method.

T-die method has an advantage of high-speed production, and in thatcase, the temperature of resin during molding only has to be not lessthan the melting temperature and lower than the decompositiontemperature of the resin, and generally an appropriate temperature is150-250° C.

Specifications and molding conditions of molding machine for theinflation method are not limited, and conventionally known methods andconditions can be used. For example, the extruder has a caliber of10-600 mm in diameter and a ratio L/D of 8-45 wherein D is the caliber,and L is a length L from the bottom of the hopper to the tip ofcylinder. The die has a shape generally used for inflation molding, forexample, has a flow geometry of a spider type, spiral type or stackingtype, and has a caliber of 1-5000 mm.

As the molding machine for calendar method, for example, any oftandem-type, L-type, reversed-L-type and Z-type can be used.

Further, the layered product of the present invention can be molded, forexample, by making a single-layer film by T-die or inflation molding andthen subjecting it to heat or extrusion lamination, but from theviewpoint of production cost, a multi-layer T-die extruder is preferablyused for molding.

The thus-obtained layered product of the present invention has athickness of preferably 30-500 μm, more preferably 40-400 μm, andfurther more preferably 50-350 μm. When the thickness is too thin, thestrength of the layered product is insufficient, and there is a risk ofbreaking the layered product in use. On the other hand, when thethickness is too thick, problems tend to arise such that the layeredproduct becomes difficult to process, flexibility of the layered productis deteriorated, or whitening occurs at folded portions.

In the layered product of the present invention, a ratio (H_(A)/H_(C))of a thickness (H_(A)) of the above layer (A) to a thickness (H_(C)) ofthe above layer (C) preferably satisfies 0.5≦H_(A)/H_(C)≦1.3 and morepreferably 0.75≦H_(A)/H_(C)≦1.25. When the layered product satisfiesthis condition, it can be prevented from curling.

Meanwhile, as long as the water vapor barrier layer (D) has a thicknessof 5-20 μm, it generates no curl or only a subtle curl that is notpractically problematic when arranged either on the outer surface of theabove layer (A) or the above layer (C) or either between the above layer(A) and the above layer (B) or the above layer (B) and the above layer(C).

In the layered product of the present invention, a ratio(H_(A)+H_(C))/H_(E) of a total thickness of the thickness (H_(A)) of theabove layer (A) and the thickness (H_(C)) of the above layer (C) to athickness (H_(E)) of the above layer (B) satisfies0.4≦(H_(A)+H_(C))/H_(B)≦2.4. When this condition is satisfied, thelayered product excellent in balance between heat resistance andflexibility can be obtained.

The thickness (H_(B)) of the layer (B) is preferably 10-200 μm and morepreferably 30-150 μm. When the layer (B) is too thin, heat resistancetends to be insufficient, and when it is too thick, flexibility tends tobe insufficient. Also, the thickness (H_(A)) of the layer (A) and thethickness (H_(C)) of the layer (C) are both preferably 10-150 μm andmore preferably 15-100 μm. When the layers (A) and (C) are too thin,flexibility tends to be insufficient, and when they are too thick, heatresistance tends to be insufficient.

Further, for example, when the thickness of the whole layered product is250 μm, the thicknesses of the layer (A)/the layer (B)/the layer (C) arepreferably 10-100/10-200/10-200 μm, more preferably 30-100/50-190/30-100μm, further more preferably 40-90/70-170/40-90 μm and particularlypreferably 50-80/90-150/50-80 μm. When the thickness of the layer (A)exceeds 100 μm, heat resistance tends to be insufficient, and on theother hand, when the thickness of the above layer (A) is less than 10μm, flexibility of the layered product film tends to be insufficient.

In addition, for example, when the thickness of the whole layeredproduct with a water vapor barrier layer (D) is 250 μm, the thicknessesof the layer (A)/the layer (B)/the layer (C)/the layer (D) arepreferably 10-100/10-200/10-200/10-100 μm, more preferably30-100/50-190/30-100/5-50 μm, further more preferably40-90/70-170/40-90/5-40 μm and particularly preferably50-80/90-150/50-80/5-20 μm. When the thickness of the layer (A) and/orthe layer (C) exceeds 100 μm, heat resistance tends to be insufficient,and on the other hand, when the thickness of the layer (A) and/or thelayer (C) is less than 30 μm, flexibility of the back sheets for solarcells tends to be insufficient.

When the infrared reflective layered product of the present inventiondoes not comprise the water vapor barrier layer (D), a protective layer(E) can be optionally layered on the outer surface of the layer (A)and/or the outer surface of the layered (C), and is preferably layeredon the outer surface of the above layer (C). Particularly, when thelayered product of the present invention is used as a back sheet forsolar cells, it is preferable that the protective layer (E) is providedon the outer surface of the above layer (C) which is positioned at theside opposite to solar cells from the viewpoint of power generationefficiency and adhesion to the solar cells.

In addition, when the infrared reflective layered product of the presentinvention comprises the water vapor barrier layer (D), a protectivelayer (E) can be optionally layered as the outermost layer on the sideof the layer (C). Particularly, when the layered product of the presentinvention is used as a back sheet for solar cells, it is preferable thatthe protective layer (E) is provided as the outermost layer on the sideof the above layer (C) which is positioned at the side opposite to solarcells from the viewpoint of power generation efficiency and adhesion tothe solar cells. For example, when the water vapor barrier layer (D) isprovided on the outer surface of the layer (A), the protective layer (E)can be layered on the outer surface of the layer (C), and when the watervapor barrier layer (D) is provided on the outer surface of the layer(C), the protective layer (E) can be layered on the outer surface of thelayer (D). Particularly, when the water vapor barrier (D) is provided onthe outer surface of the layer (C), a vapor-deposited layer of the watervapor barrier layer (D) is positioned to be the outer surface, and thusthe protective layer (E) layered thereon can function to protect thevapor-deposited layer, thereby improving durability of the water vaporbarrier property. On the other hand, since the layer (A) is layered on asolar cell, high adhesion between the layered product and solar cellscan be achieved.

The protective layer (E) is frequently used in cover films and backsheets for solar cells for improving physical properties such as scratchresistance and penetration resistance, chemical properties such aschemical resistance or thermal properties such as flame resistance, and,in the present invention, is preferably one which can improve flameresistance and scratch resistance of the layered product.

Such a protective layer (E) includes, for example, fluorocarbon resinfilms such as polyvinylfluoride film and ethylene-tetrafluoroethylenecopolymer film, polycarbonate film, polyarylate film, polyethersulfonefilm, polysulfone film, polyacrylonitrile film, polyethyleneterephthalate (PET) film with hydrolytic resistance, polyethylenenaphthalate (PEN) film with hydrolytic resistance, cellulose acetatefilm, acrylic resin film, polypropylene film with weatherability, glassfiber-reinforced polyester film, glass fiber-reinforced acrylic resinfilm and glass fiber-reinforced polycarbonate film. Of these, as theprotective layer used in the present invention, fluorocarbon resin film,polyethylene terephthalate film with hydrolytic resistance andpolyethylene naphthalate film with hydrolytic resistance are preferabledue to excellent flame resistance and scratch resistance. These can beused as a single film or a laminated film of two or more layers.

The thickness of the protective layer (E) is preferably 25-300 μm andmore preferably 25-200 μm. When the thickness of the protective layer(E) is less than 25 μm, the effect of protecting the layered product isinsufficient. When the thickness of the protective layer (E) exceeds 300μm, flexibility of the layered product is insufficient, and also theweight of the layered product is increased, and thus this is notpreferable.

Further, in the infrared reflective layered product of the presentinvention, the layer (A) is usually used as a surface for receiving alight such as sunlight, and thus it can be provided with a pressuresensitive adhesive layer or adhesive layer on a surface of the layer(C), (D) or (E) as the back in order to obtain a cohesive film, adhesivefilm, cohesive sheet or adhesive sheet. A protective layer can befurther provided on a surface of a cohesive layer or adhesive layer soas to protect these layers.

If required, another layer may be layered between the respective layersof the layered product, which includes a decorative layer, and a layermade of a recycle resin (usually, the thermoplastic resin (I), thethermoplastic resin (II) and a blend of these ingredients) generatedduring production, as long as the effect of the present invention is notimpaired.

The infrared reflective layered product of the present invention issuitably used as a back sheet for solar cells, especially a back sheetfor solar cells of crystalline silicon type, as well as others includinginterior materials for automobiles, building materials, and coloredreflective plates for infrared heaters.

A solar cell module using the back sheet for solar cells of the presentinvention is usually composed of a transparent substrate such as glass,a sealing film, a solar cell element, a sealing film and the back sheetfor solar cells of the present invention in this order from the sunlightreceiving surface side. Of these, the transparent substrate, the sealingfilm, the solar cell element and the sealing film constitute the solarbattery silicon cell.

As the transparent substrate, generally glass is used. Since glass isexcellent in transparency and weatherability but low in impactresistance and heavy, a transparent resin with weatherability is alsopreferably used for the solar cells placed on the roof of ordinaryhouses. The transparent resin includes a fluorocarbon resin film. Thethickness of the transparent substrate is usually 3-5 mm when glass isused, and usually 0.2-0.6 mm when a transparent resin is used.

As the sealing film, an olefin resin is used. Here, the olefin resincollectively refers to polymers resulting from polymerization orcopolymerization of an olefin such as ethylene, propylene, butadiene andisoprene or a diolefin, and includes copolymers of ethylene with anothermonomer such as vinyl acetate and acrylic acid esters and ionomersthereof. Concretely, it includes polyethylene, polypropylene,polymethylpentene, ethylene/vinyl chloride copolymer,ethylene/vinylacetate copolymer (EVA), ethylene/vinyl alcohol copolymer,chlorinated polyethylene and chlorinated polypropylene, and of these,EVA is widely used. EVA may be painted as a cohesive agent or adhesiveagent or used in a sheet form, but generally is used in a sheet formwhich is heat-pressed. When it is used in a sheet form, the thicknessthereof is usually 0.2-5.0 mm.

As the solar cell element, a known silicon can be used. The silicon maybe amorphous silicon, monocrystalline silicon or polycrystallinesilicon, and preferably polycrystalline silicon. This is due to thefollowing reasons. Comparing a response bandwidth of solar spectrum ofamorphous silicon and polycrystalline silicon, a response bandwidth ofamorphous silicone is present in a visible light side, while a responsebandwidth of polycrystalline silicone is present in an infrared side.Distribution of solar energy is about 3% in ultraviolet region, about47% in visible light region, and about 50% in infrared region, and thusthe energy proportion of an infrared region is large. Thus, the use ofthe back sheet for solar cells of the present invention having not onlylow heat storage but also infrared reflective property in combinationwith polycrystalline silicon as the solar cell element may furtherimprove the power generation efficiency.

The above structural units of the solar cell module can be bondedtogether using an adhesive agent. As the adhesive agent, known adhesiveagents can be used, for example, butyl rubber adhesive agents, siliconeadhesive agents and EPDM adhesive agents are included.

EXAMPLE

Hereinafter, the present invention will be described in more detail byway of Examples. However, the present invention is in no way restrictedto the following Examples. The units “parts” and “%” in Examples andComparative Examples are on mass basis unless otherwise specified.

1. Evaluation Method

The measurement methods for various evaluation items in the followingExamples and Comparative Examples are shown below.

1-1. Rubber Content of Thermoplastic Resins (I) and (II)

It was calculated from a composition of raw materials.

1-2. Content of N-Phenylmaleimide Unit

It was calculated from a composition of raw materials.

1-3. Glass Transition Temperature (Tg)

It was measured using differential scanning calorimeter of type DSC2910(trade name; manufactured by TA Instruments) in accordance with JIS K7121.

1-4. Absorptance (%) of a Light with a Wavelength of 800-1400 nm of theLayer (A) Alone

A layer (A) with a thickness shown in Tables 4 to 7 was singly formed asa film with a T-die, and then a test piece thereof (50 mm×50 mm) wasused to measure a transmittance and a reflectance in a range ofwavelength of 800-1400 nm with V-670 (wavelength range of 200-2700 nm)manufactured by JASCO Corporation, and an absorptance was determinedbased on the following equation.

Absorptance(%)=100−(transmittance(%)+reflectance(%))

1-5. Reflectance (%) of a Light with a Wavelength of 400-1400 nm of theLayer (C) Alone

A layer (C) with a thickness shown in Tables 4 to 7 was singly formed asa film with a T-die, and then a test piece thereof (50 mm×50 mm) wasused to measure a reflectance in a range of wavelength of 400-1400 nmwith V-670 (wavelength 200-2700 nm) manufactured by JASCO Corporation.

1-6. L Value

L value of a single layer was measured using a test piece of 50 mm×50mm×100 u with an absorption spectrophotometer TCS-II manufactured byToyo Seiki Seisaku-sho, Ltd. L value of a layered product was obtainedby measuring each surface of the resulting layered product.

1-7. Heat Resistance 1-7-1. Dimensional Change (%) of a Layer (B) AloneAfter Heating at 150° C. for 30 min.

A layer (B) with a thickness shown in Tables 4-7 was singly formed as afilm with a T-die, and then a square of 50 mm (MD)×50 mm (TD) was drawnon the center of a surface of a test piece of 100 mm (MD: extrudingdirection of a resin from T-die)×100 mm (TD: vertical direction to MD),and the test piece was heated and left at 150° C. for 30 minutes in athermostatic chamber, and then taken out to measure a dimensional changeof each side in MD and TD directions of the test piece. The length afterheating was taken as an average of the measured values of length of therespective sides in MD and TD directions of the above square. Theshrinkage (s) was determined based on the following equation from themeasured dimensions before and after heating.

${{Shrinkage}\mspace{14mu} (\%)} = {\frac{\begin{matrix}{\left( {{Length}\mspace{14mu} {after}\mspace{14mu} {heating}} \right) -} \\\left( {{Length}\mspace{14mu} {before}\mspace{14mu} {heating}\text{:}\mspace{14mu} 50\mspace{14mu} {mm}} \right)\end{matrix}}{\left( {{Length}\mspace{14mu} {before}\mspace{14mu} {heating}\text{:}\mspace{14mu} 50\mspace{14mu} {mm}} \right)} \times 100}$

Meanwhile, the following shrinkage (s) shows a negative value when atest piece shrinks after heating and a positive value when a test pieceexpands after heating.

1-7-2. Dimensional Change of the Layered Product after Heating at 150°C. for 30 min.

It was measured in the same method as above in 1-7-1 except that alayered product was used instead of the layer (B).

1-8. Flexibility (Bending Test)

A test piece of 100 mm (MD)×100 mm (TD) was cut out from a layeredproduct, bended along an axis of symmetry in MD direction, and thenalong an axis of symmetry in TD direction. A manual pressing roll (2000g) was used to make two round trips on each crease of the bended testpiece at a speed of 5 mm/sec in accordance with JIS Z0237. Then, thecrease was unfolded to return to an original condition, and thecondition of the test piece was visually observed. Criteria are shownbelow. In the test results, one having no crack of crease is excellentin flexibility.

©: No crease was cracked, and further bending and unfolding did notcause the crease to crack.◯: No crease was cracked, but further bending and unfolding caused thecrease to crack.X: A crease was cracked.

1-9. Hydrolytic Resistance (Pressure Cooker Test) 1-9-1. Retention ofFracture Stress

A test piece of 150 mm (MD)×15 mm (TD) was cut out from a layeredproduct, and left under the condition with a temperature of 120° C. anda humidity of 100% for 100 or 200 hours, and then fracture stress of thetest piece was measured in accordance with JIS K 7127 using an AG2000tensile testing machine (manufactured by SHIMADZU CORPORATION). Adistance between chucks at the time of sample setting was 100 mm andtensile rate was 300 mm/min. From the resulting measured values offracture stress, retention of fracture stress was determined by thefollowing equation.

${{Retention}\mspace{14mu} {of}\mspace{14mu} {fracture}\mspace{14mu} {stress}\mspace{14mu} (\%)} = {\frac{{Fracture}\mspace{14mu} {stress}\mspace{14mu} {of}\mspace{14mu} {test}\mspace{14mu} {piece}\mspace{14mu} {after}\mspace{14mu} {leaving}}{{Fracture}\mspace{14mu} {stress}\mspace{14mu} {of}\mspace{14mu} {test}\mspace{14mu} {piece}\mspace{14mu} {before}\mspace{14mu} {leaving}} \times 100}$

Hydrolytic resistance was evaluated based on the obtained retention offracture stress according to the following criteria. The higher theretention is, the better the hydrolytic resistance is.

◯: retention of fracture stress exceeds 80%.Δ: retention of fracture stress is 50-80%.X: retention of fracture stress is less than 50%.

1-9-2. Retention of Elongation

Fracture elongation was measured simultaneously with the measurement ofthe above 1-9-1. Retention of elongation was determined by the followingequation from the resulting measured value of elongation.

${{Retention}\mspace{14mu} {of}\mspace{14mu} {elongation}\mspace{14mu} (\%)} = {\frac{{Fracture}\mspace{14mu} {elongation}\mspace{14mu} {of}\mspace{14mu} {test}\mspace{14mu} {piece}\mspace{14mu} {after}\mspace{14mu} {leaving}}{{Fracture}\mspace{14mu} {elongation}\mspace{14mu} {of}\mspace{14mu} {test}\mspace{14mu} {piece}\mspace{14mu} {before}\mspace{14mu} {leaving}} \times 100}$

Hydrolytic resistance was evaluated based on the obtained retention ofelongation according to the following criteria. The higher the retentionis, the better the hydrolytic resistance is.

◯: retention of elongation exceeds 80%.Δ: retention of elongation is 50-80%X: retention of elongation is less than 50%

1-9-3. Measurement of Curl (Deformation)

A test piece of 150 mm (MD)×15 mm (TD) was cut out from a layeredproduct, and was left under the condition with a temperature of 120° C.and a humidity of 100% for 100 or 200 hours, and then curl (deformation)of the test piece was visually observed and evaluated according to thefollowing criteria.

◯: no curl (deformation).X: there is curl (deformation).

1-10. Improvement Rate of Conversion Efficiency

In a chamber which was conditioned at a temperature of 25° C.±2° C. andhumidity of 50±5% RH, a ¼ polycrystalline silicone cell which had beenpreviously measured for its conversion efficiency was provided on thefront side thereof with a glass having a thickness of 3 mm and on theback side thereof with a layered product, and then encapsulated in EVAto prepare a module, and measured for conversion efficiency using asolar simulator PEC-11 manufactured by Peccell. Meanwhile, in order tolower the effect of temperature, conversion efficiency was measuredimmediately after irradiation with light. Improvement rate of conversionefficiency was determined by the next equation. The higher theimprovement rate of the above conversion efficiency is, the higher thepower generation efficiency of solar cells is.

${{Improvement}\mspace{14mu} {rate}\mspace{14mu} {of}\mspace{14mu} {conversion}\mspace{14mu} {efficiency}\mspace{14mu} (\%)} = {{- \frac{\begin{matrix}{\left( {{conversion}\mspace{14mu} {efficiency}\mspace{14mu} {of}\mspace{14mu} {module}} \right) -} \\{\left( {{conversion}\mspace{14mu} {efficiency}\mspace{14mu} {of}\mspace{14mu} {cell}\mspace{14mu} {alone}} \right) -}\end{matrix}}{{conversion}\mspace{14mu} {efficiency}\mspace{14mu} {of}\mspace{14mu} {cell}\mspace{14mu} {alone}}} \times 100}$

1-11. Heat Storage

In a chamber which was conditioned at a temperature of 25° C.±2° C. andhumidity of 50±5% RH, the surface (the surface on the layer (A) side) ofa test piece of 80 mm×50 mm (with a thickness shown in Tables 4-7) of alayered product was irradiated with an infrared lamp (output: 100W) fromthe height of 200 mm, and a surface temperature of the test piece after60 minutes was measured using a surface thermometer. The unit is ° C.

1-12. Weatherability

Metaling Weather Meter MV3000 (manufactured by Suga Test InstrumentsCo., Ltd.) was used to perform an exposure test for a test piece of 50mm (MD)×30 mm (TD) which was cut out from a layered product, byrepeating conditions of steps 1-4 shown below, and a color change valueΔE between before exposure and 100 hours after exposure was calculated.

Meanwhile, the surface on the side of layer (A) of the layered productwas exposed.

Step 1: irradiation 0.53 kW/m², 63° C., 50% RH, 4 h Step 2:irradiation + 0.53 kW/m², 63° C., 95% RH, 1 min raining Step 3: darkness0 kW/m², 30° C., 98% RH, 4 h Step 4: irradiation + 0.53 kW/m², 63° C.,95% RH, 1 min rainingLab (L: brightness, a: redness, b: yellowness) was measured usingSpectrophotometer V670 (manufactured by JASCO Corporation), and ΔE wascalculated by the next equation.

ΔE=√[(L ₁ −L ₂)²+(a ₁ −a ₂)²+(b ₁ −b ₂)²]

wherein, L₁, a₁ and b₁ indicate values before exposure, and L₂, a₂ andb₂ indicate values after exposure. The smaller the ΔE value is, thesmaller the color change is and the better the weatherability is.Evaluation standards are shown as follows.◯: ΔE is not more than 10.X: ΔE exceeds 10.

1-13. Water Vapor Barrier Property (Water Vapor Permeability Test)

It was measured in accordance with JIS K 7129B under the followingconditions.

Test device: PERMATRAN W3/31 (manufactured by MOCON)Test temperature: 40° C.Test humidity: 90% RH (practically measured humidity)Permeation face: the layer (C) side of the layered product was arrangedon water vapor side.

1-14. Flame Resistance

Using a burner for UL94 V-test, a lower end of a test piece (width: 20mm×Length: 100 mm) suspended with shorter side at the top was fired for5 seconds under the condition that the test piece was 10 mm away fromthe tip of the burner. After the completion of firing, a combustioncondition of the fired part of the test piece was visually observed, andevaluated under the following standards.

◯: there is no burningX: there is burning

1-15. Scratch Resistance

Using a reciprocating friction tester manufactured by Tosoku SeimitsuKogyo Kabushiki-Kaisha, a surface of a test piece was rubbed 500 timesby reciprocation with a cotton canvas cloth No. 3 under a vertical loadof 500 g, and then the surface was visually observed and evaluated underthe following standards.

◯: no scratch is observed.Δ: a little scratch is observed.X: scratch is observed clearly.

2. Method for Producing a Layered Product 2-1. Materials to be Used2-1-1. Butadiene Rubber-Reinforced Styrene Resin

[Preparation of Butadiene Graft Copolymer (a)]

In a glass reaction vessel equipped with a stirrer, 75 parts ofion-exchanged water, 0.5 part of potassium rosinate, 0.1 part oft-dodecylmercaptane, 32 parts (as solid matter) of polybutadiene latex(average particle diameter: 270 nm, gel content: 90%), 8 parts ofstyrene-butadiene copolymer latex (styrene content: 25%, averageparticle diameter: 550 nm), 15 parts of styrene and 5 parts ofacrylonitrile were placed, and the mixture was heated under nitrogenstream while stirring. When the inner temperature reached 45° C., asolution of 0.2 part of sodium pyrophosphate, 0.01 part of ferroussulfate 7-hydrate and 0.2 part of glucose in 20 parts of ion-exchangedwater was added thereto. Then, 0.07 part of cumene hydroperoxide wasadded to initiate polymerization, and polymerization was effected forone hour. Next, 50 parts of ion-exchanged water, 0.7 part of potassiumrosinate, 30 parts of styrene, 10 parts of acrylonitrile, 0.05 part oft-dodecylmercaptane and 0.01 part of cumene hydroperoxide were addedcontinuously for 3 hours. After polymerization was effected for onehour, 0.2 part of 2,2′-methylene-bis(4-ethylene-6-t-butylphenol) wasadded to terminate the polymerization. Magnesium sulfate was added tothe latex to coagulate resinous components. Then, the resultant waswashed with water and further dried to obtain a polybutadiene graftcopolymer (a). The graft ratio was 72%, and the limiting viscosity (η)of the acetone soluble matter was 0.47 dl/g.

2-1-2. Silicone/Acrylic Composite Rubber-Reinforced Styrene Resin

“METABLEN SX-006 (trade name)” manufactured by MITSUBISHI RAYON CO.,LTD. (a resin modifier which is an acrylonitrile-styrene copolymergrafted onto a silicone/acrylic composite rubber with a rubber contentof 50%, a graft ratio of 80%, a limiting viscosity [η] (at 30° C. inmethyl ethyl ketone) of 0.38 dl/g and a glass transition temperature(Tg) of 135° C.) was used.

2-1-3. Silicone Rubber-Reinforced Styrene Resin/AcrylicRubber-Reinforced Styrene Resin Mixture

[Preparation of Silicone Rubber-Reinforced Styrene Resin (b-1)]

1.3 parts of p-vinylphenylmethyldimethoxysilane and 98.7 parts ofoctamethylcyclotetrasiloxane were mixed, and placed in a solution of 2.0parts of dodecylbenzene sulfonic acid in 300 parts of distilled water,and stirred with a homogenizer for 3 minutes to perform emulsificationand dispersion. The mixture was poured into a separable flask equippedwith a condenser, nitrogen introducing opening and stirrer, and heatedat 90° C. for 6 hours and maintained at 5° C. for 24 hours understirring and mixing to complete condensation. The resultingpolyorganosiloxane rubber-like polymer had a condensation ratio of 93%.This latex was neutralized to pH 7 with an aqueous sodium carbonatesolution. The resulting polyorganosiloxane rubber-like polymer latex hadan average particle diameter of 0.3 μm.

In a glass flask having an internal volume of 7 liters and equipped witha stirrer, the ingredients for batch-polymerization comprising 100 partsof ion-exchanged water, 1.5 parts of potassium oleate, 0.01 part ofpotassium hydroxide, 0.1 part of t-dodecylmercaptane, 40 parts (as solidmatter) of the above polyorganosiloxane latex, 15 parts of styrene and 5parts of acrylonitrile were added thereto, and heated under stirring.When a temperature reached 45° C., an activating solution comprising 0.1part of ethylenediaminetetraacetic acid, 0.003 part of ferrous sulfate,0.2 part of formaldehyde sodium sulfoxylate dihydrate and 15 parts ofion-exchanged water, and 0.1 part of diisopropylbenzene hydroperoxidewas added, and reaction was continued for an hour.

Then, a mixture of incremental polymerization ingredients comprising 50parts of ion-exchanged water, 1 part of potassium oleate, 0.02 part ofpotassium hydroxide, 0.1 part of t-dodecylmercaptane and 0.2 part ofdiisopropylbenzene hydroperoxide as well as the monomers of 30 parts ofstyrene and 10 parts of acrylonitrile was added continuously over 3hours to continue the reaction. After the completion of addition,reaction was further continued for an hour under stirring, and then 0.2part of 2,2-methylene-bis-(4-ethylene-6-t-butylphenol) was added theretoto obtain a polymer latex. Further, 1.5 parts of sulfuric acid was addedto the above latex and allowed to coagulate at 90° C., and dehydration,washing with water and drying were performed to obtain a siliconerubber-reinforced styrene resin (b-1) in a powder form. The graft ratiothereof was 84% and the limiting viscosity [η](at 30° C. in methyl ethylketone) was 0.60 dl/g.

[Preparation of Acrylic Rubber-Reinforced Styrene Resin (b-2)]

In a reaction vessel, 50 parts (as solid matter) of a latex with a solidcontent of 40% of an acrylic rubber-like polymer (with a volume averageparticle diameter of 100 nm and a gel content of 90%) obtained byemulsion polymerization of 99 parts of n-butyl acrylate and 1 part ofallylmethacrylate was placed, and further 1 part of sodiumdodecylbenzene sulfonate and 150 parts of ion-exchanged water wereplaced for dilution. Then, the inside of the reaction vessel was purgedwith nitrogen, 0.02 part of ethylenediaminetetraacetic acid disodiumsalt, 0.005 part of ferrous sulfate and 0.3 part of sodium formaldehydesulfoxylate were added thereto, and heated to 60° C. under stirring.

On the other hand, in a vessel, 1.0 part of terpinolene and 0.2 part ofcumene hydroperoxide were dissolved in 50 parts of a mixture of 37.5parts of styrene and 12.5 acrylonitrile, and then the inside of thevessel was purged with nitrogen to obtain a monomer composition.

Next, the above monomer composition was polymerized at 70° C. whilst itwas added to the above reaction vessel at a constant flow rate over 5hours, to obtain latex. Magnesium sulfate was added to the latex tocoagulate resinous components. Then, the resultant was washed with waterand further dried to obtain an acrylic rubber-reinforced styrene resin(b-2). The graft ratio thereof was 93% and the limiting viscosity [η](at 30° C. in methyl ethyl ketone) was 0.30 dl/g.

2-1-4. Styrene-Acrylonitrile Copolymer

“SAN-H (trade name)” manufactured by Techno Polymer Co., Ltd. (ASresin).

2-1-5. N-phenylmaleimide-acrylonitrile-styrene copolymer

“POLYIMILEX PAS1460 (trade name)” manufactured by NIPPON SHOKUBAI CO.,LTD. (N-phenylmaleimide-acrylonitrile-styrene copolymer with anN-phenylmaleimide content of 40%)

2-1-6. Polyethylene Terephthalate

“NOVAPEX GM700Z (trade name)” manufactured by Mitsubishi ChemicalCorporation was used. It had a glass transition temperature (Tg) of 75°C.

2-1-7. Infrared Transmittable Organic Black Pigment (transmittableblack)

“Lumogne Black FK4280 (trade name)” manufactured by BASF

2-1-8. Carbon Black (Black)

“Carbon black #45(trade name)” manufactured by Mitsubishi ChemicalCorporation

2-1-9. Titanium Oxide (White)

“TIPAQUE CR-60-2 (trade name)” manufactured by ISHIHARA SANGYO KAISHA,LTD

2-2. Layer (A) (Infrared Transmittable Colored Resin Layer)

The components shown in Table 1 were mixed together in a Henschel mixerin a proportion shown in Table 1, and then melt-kneaded in adouble-screw extruder (TEX44 manufactured by The Japan Steel Works,LTD., a barrel temperature of 270° C.) to obtain pellets. The resultingcomposition was evaluated in accordance with the above evaluationmethods. The results are shown in Table 1.

TABLE 1 Layer (A) Layer (C) ASA-1*¹ ASA-6*² ABS-1 ASA-9*² PET-1 ASA-2*¹ASA-8*¹ ABS-2 PET-2 Thermoplastic Butadiene rubber-reinforced — — 40 — —— — 40 — Resin (II) styrene resin (part) Silicone/acrylic composite 30 —— — — 30 30 — — rubber-reinforced styrene resin (part) Siliconerubber-reinforced — 10 — 10 — — — — — styrene resin (part) Acrylicrubber-reinforced — 22 — 22 — — — — — styrene resin (part)Styrene-acrylonitrile copolymer 30 28 20 28 — 30 30 20 — (part)N-phenylmaleimide-acrylonitrile- 40 40 40 40 — 40 40 40 — styrenecopolymer (part) Polyethylene terephthalate — — — — 100  — — — 100 (part) Pigment Infrared transmittable organic  3  3  2 —  4 — — — —black pigment (part) Carbon black (part) — — —  5 — — — — — Titaniumoxide (part) — — — — 20  2 25 15 Evaluation Rubber content (%) 15 15 1615 — 15 15 16 — Result N-phenylmaleimide unit content 16 16 16 16 — 1616 16 — (%) Glass transition temperature 135  135  135  135  75 135 135  135  75 (Tg) (° C.) 100μ mono layer L value 29 28 28 24 28 97 65 9796 *¹Silicone/acrylic composite rubber 100%. *²Combined use of 26.7%silicone rubber and 73.3% acrylic rubber.

2-3. Layer (B) (Base Layer)

The components shown in Table 2 were mixed together in a Henschel mixerin a proportion shown in Table 2, and then melt-kneaded in adouble-screw extruder (TEX44 manufactured by The Japan Steel Works,LTD., a barrel temperature of 270° C.) to obtain pellets. The resultingcomposition was evaluated in accordance with the above evaluationmethods. The results are shown in Table 2.

TABLE 2 Layer (B) ASA-3*¹ ASA-4*² ASA-5*¹ ABS-3 ASA-7*¹ PET-3Thermoplastic Butadiene rubber-reinforced — — — 40 — — Resin (I) styreneresin (part) Silicone/acrylic composite 30 — 30 — 30 — rubber-reinforcedstyrene resin (part) Silicone rubber-reinforced — 10 — — — — styreneresin (part) Acrylic rubber-reinforced — 22 — — — — styrene resin (part)Styrene-acrylonitrile copolymer  8  6  8 — 70 — (part)N-phenylmaleimide-acrylonitrile- 62 62 62 60 — — styrene copolymer(part) Polyethylene terephthalate — — — — — 100  (part) Pigment Titaniumoxide (white) (part) — — 20 — — — Evaluation Rubber content (%) 15 15 1516 15 — Result N-phenylmaleimide unit content   24.8   24.8   24.8 24  0— (%) Glass transition temperature 155  155  155  155  108  75 (Tg) (°C.) 100μ mono layer L value 56 57 97 56 56 43 *¹Silicone/acryliccomposite rubber 100%. *²Combined use of 26.7% silicone rubber and 73.3%acrylic rubber.

2-4. Layer (C) (Infrared Reflective Colored Resin Layer)

The components shown in Table 1 were mixed together in a Henschel mixerin a proportion shown in Table 1, and then melt-kneaded in adouble-screw extruder (TEX44 manufactured by The Japan Steel Works,LTD., a barrel temperature of 270° C.) to obtain pellets. The resultingcomposition was evaluated in accordance with the above evaluationmethods. The results are shown in Table 1.

2-5. Layer (D) (Water Vapor Barrier Layer)

A water vapor barrier layer shown in Table 3 was used. These water vaporbarrier films are those comprising a transparent polyethyleneterephthalate (PET) film which is formed on one surface thereof with atransparent thin film layer made of a metal and/or metal oxide as awater vapor barrier layer. Meanwhile, in Table 3, moisture permeability,total light transmittance and haze were respectively measured inaccordance with the methods described above.

TABLE 3 Thick- Moisture Total light ness permeability transmittance HazeTrade name (μ) (g/m² · d) (%) (%) WVB-1 “TECHBARRIER 12 0.15 89 4.0 AX”manufactured by MITSUBISHI PLASTICS, INC. WVB-2 “ECOSYAR 12 0.5 90 2.6VE500” manufactured by Toyobo Co., Ltd.

2-6. Layer (E) (Protective Layer)

The following commercially available PET films were used.

(E-1): “LUMIRROR X10S (trade name)” manufactured by TORAY INDUSTRIESINC. with a thickness of 50 μm.(E-2): “Melinex 238 (trade name)” manufactured by Teijin Dupont FilmJapan Limited with a thickness of 75 μm.

3. Production of Layered Film 3-1. Examples I-1 to I-7, ComparativeExamples I-1 to I-4

Films were produced by the following method.

First, a multi-layer film molding machine provided with T-die (diewidth; 1400 mm, lip distance; 0.5 mm) and three extruders with a screwdiameter of 65 mm was provided, and each pellet of the above layer (A),(B) and (C) was supplied to the respective extruders as shown in Table 4so that the resins were ejected at a melting temperature of 270° C. fromthe T-die to produce a soft film. Then, the soft film was brought intosurface-to-surface contact with a cast roll (roll surface temperature;95° C.) by air knife, and cooled and solidified to obtain a film. Inthis instance, by adjusting operation conditions of the extruders andcast roll, the thickness of the whole film and the respectivethicknesses of layer (A)/layer (B)/layer (C) were controlled to thevalues shown in Table 4. The evaluation results of the resulting filmsare shown in Tables 4.

Meanwhile, the thickness of the film was measured by cutting out a filmone hour after the initiation of production of the film, and measuring athickness at the center and each site at an interval of 10 mm from thecenter to both terminals in the transverse direction of the film using athickness gage (type “ID-C1112C” manufactured by Mitutoyo Corporation),and was taken as an average value thereof. Values measured at siteswithin a range of 20 mm from the film terminals were omitted from thecalculation of the above average value.

TABLE 4 Comp. Comp. Comp. Comp. Ex. I-1 Ex. I-2 Ex. I-3 Ex. I-4 Ex. I-5Ex. I-6 Ex. I-7 Ex. I-1 Ex. I-2 Ex. I-3 Ex. I-4 Layer Layer (A) MaterialASA-1 ASA-1 ASA-1 ASA-6 ASA-1 ABS-1 PET-1 ASA-9 ASA-1 — ASA-1constitution Tg (° C.) 135 135 135 135 135 135 75 135 135 — 135 Pigmentcolor Trans- Trans- Trans- Trans- Trans- Trans- Trans- CB Trans- —Trans- mit- mit- mit- mit- mit- mit- mit- mit- mit- table table tabletable table table table table table black black black black black blackblack black black Thickness (μ) 20 30 30 30 30 30 40 30 30 0 30 Layer(B) Material ASA-3 ASA-3 ASA-4 ASA-3 ASA-4 ABS-3 PET-3 ASA-3 — ASA-3ASA-7 Tg (° C.) 155 155 155 155 155 155 75 155 — 155 108 Pigment color —— — — — — — — — White — Thickness (μ) 60 100 150 100 150 100 70 100 0200 100 Layer (C) Material ASA-2 ASA-2 ASA-2 ASA-2 ASA-8 ABS-2 PET-2ASA-2 ASA-2 — ASA-2 Tg (° C.) 135 135 135 135 135 135 75 135 135 — 135Pigment color White White White White White White White White WhiteWhite Thickness (μ) 60 100 150 100 100 100 40 100 200 0 60 Thickness ofthe whole 140 230 330 230 280 230 150 230 230 200 190 layered product(μ) Difference between Tg of 20 20 20 20 20 20 0 20 — — −27 layer (B)and Tg of layer (A) (° C.) Difference between Tg of 20 20 20 20 20 20 020 — — −27 layer (B) and Tg of layer (C) (° C.) Absorptance of a lightwith a 5 5 6 5 5 5 7 88 6 — 6 wavelength of 800-1400 nm of layer (A)alone (%) Reflectance of a light with a 75 87 90 86 55 85 72 87 85 — 77wavelength of 800-1400 nm of layer (C) alone (%) Evaluation L value ofsurface of layer (A) 34 29 29 28 28 27 25 25 28 — 27 results of layeredproduct L value of surface of layer (C) 83 92 93 93 57 91 79 91 91 — 86of layered product Heat resistance: dimensional 0.4 0.4 0.3 0.4 0.4 0.40.4 0.4 1.4 0.3 1.5 change after 30 min. at 150° C. of layer (B) aloneFlexibility (bending test) ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ X ⊚ Hydrolytic 100Retention ◯ ◯ ◯ ◯ ◯ ◯ X ◯ ◯ ◯ ◯ resistance hours of (pressure laterfracture cooker stress test) Retention ◯ ◯ ◯ ◯ ◯ ◯ X ◯ ◯ ◯ ◯ of elong-ation 200 Retention ◯ ◯ ◯ ◯ ◯ ◯ X ◯ ◯ ◯ ◯ hours of later fracture stressRetention ◯ ◯ ◯ ◯ ◯ ◯ X ◯ ◯ ◯ ◯ of elong- ation Improvement rate of 9 1013 10 4 10 9 0 10 14 10 conversion efficiency (%) Heat storage (° C.) 5152 53 52 53 55 52 81 52 48 51 Weatherability ◯ ◯ ◯ ◯ ◯ X X ◯ ◯ ◯ ◯

The followings are clear from Table 4. Examples I-1 to I-7 involving thelayered product comprising the layer (A), layer (B) and layer (C) of thepresent invention were excellent in flexibility and had a surface whichwas made of a colored resin but was good in infrared transmittability,low in heat storage and excellent in heat resistance, and was improvedin power generation efficiency. Also, Examples I-1 to I-5 involving useof a silicone/acrylic composite rubber-reinforced styrene resin or useof a mixture of a silicone rubber-reinforced styrene resin and anacrylic rubber-reinforced styrene resin for all the layers (A), (B) and(C) were further excellent in weatherability and hydrolytic resistance.

Comparative Example I-1 involving the layer (A) in which infraredabsorbable carbon black was used instead of an infrared transmittablecoloring agent was high in heat storage, and inferior in powergeneration efficiency. Comparative Example I-2 involving the layeredproduct without the present layer (B) was inferior in heat resistance.Comparative Example I-3 involving use of the present layer (B) alonethat further contained titanium oxide as a pigment was inferior inflexibility. Comparative Example I-4 in which the layer (B) did notsatisfy the requirement of heat resistance according to the presentinvention was inferior in heat resistance.

3-2. Examples II-1 to II-7, Comparative Examples II-1 to II-5

A film was produced by the following method.

First, a multi-layer film molding machine provided with T-die (diewidth; 1400 mm, lip distance; 0.5 mm) and three extruders with a screwdiameter of 65 mm was provided, and each pellet of the above layer (A),(B) and (C) was supplied to the respective extruders as shown in Table 5so that the resins were ejected at a melting temperature of 270° C. fromthe T-die to produce a soft film. Then, the soft film was brought intosurface-to-surface contact with a cast roll (roll surface temperature;95° C.) by air knife, and cooled and solidified to obtain a film. Inthis instance, by adjusting operation conditions of the extruders andcast roll, the thickness of the whole film and the respectivethicknesses of layer (A)/layer (B)/layer (C) were controlled to thevalues shown in Table 5. Then, a layer (D) formed of a film shown inTable 5 was stuck to a surface of a layer (A) of the resulting filmusing an adhesive agent shown in Table 5. In this instance, a thin filmlayer (water vapor barrier layer) of the water vapor barrier filmconstituting the layer (D) was layered on the layer (A) side. That is, alayered product with a structure shown in FIG. 1 was obtained. Theevaluation results of the resulting film were shown in Table 5.

Meanwhile, a thickness of a film was determined in the same manner asabove in item 3-1 (Examples I-1 to I-7 and Comparative Example I-1 toI-4).

TABLE 5 Ex. II-1 Ex. II-2 Ex. II-3 Ex. II-4 Ex. II-5 Ex. II-6 LayerLayer (A) Material ASA-1 ASA-1 ASA-1 ASA-6 ASA-1 ABS-1 constitution Tg(° C.) 135 135 135 135 135 135 Pigment color Transmit- Transmit-Transmit- Transmit- Transmit- Transmit- table table table table tabletable black black black black black black Thickness (μ) 20 30 30 30 3030 Layer (B) Material ASA-3 ASA-3 ASA-4 ASA-3 ASA-4 ABS-3 Tg (° C.) 155155 155 155 155 155 Pigment color — — — — — — Thickness (μ) 60 100 150100 150 100 Layer (C) Material ASA-2 ASA-2 ASA-2 ASA-2 ASA-8 ABS-2 Tg (°C.) 135 135 135 135 135 135 Pigment color White White White White WhiteWhite Thickness (μ) 60 100 150 100 100 100 Layer (D) Film Material WVB-1WVB-1 WVB-2 WVB-2 WVB-2 WVB-1 Thickness (μ) 12 12 12 12 12 12 AdhesiveMaterial Poly- Poly- Poly- Poly- Poly- Poly- layer urethane urethaneurethane urethane urethane urethane Thickness (μ) 5 3 5 5 3 3 Thicknessof the whole layered product (μ) 157 245 347 247 295 245 Differencebetween Tg of layer (B) and Tg of layer (A) (° C.) 20 20 20 20 20 20Difference between Tg of layer (B) and Tg of layer (C) (° C.) 20 20 2020 20 20 Absorptance of a light with a wavelength of 800-1400 nm of 5 56 5 5 5 layer (A) alone (%) Reflectance of a light with a wavelength of400-1400 nm of 75 87 90 86 55 85 layer (C) alone (%) Evaluation L valueof surface on the layer (A) side of layered product 34 29 29 28 28 27results L value of surface on the layer (C) side of layered product 8392 93 93 57 91 Heat resistance: dimensional change after 30 min. at 150°C. 0.4 0.4 0.3 0.4 0.4 0.4 of layer (B) alone (%) Flexibility (bendingtest) ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ Hydrolytic resistance 100 hours Retention of fracturestress ◯ ◯ ◯ ◯ ◯ ◯ (pressure cooker test) later Retention of elongation◯ ◯ ◯ ◯ ◯ ◯ 200 hours Retention of fracture stress ◯ ◯ ◯ ◯ ◯ ◯ laterRetention of elongation ◯ ◯ ◯ ◯ ◯ ◯ Improvement rate of conversionefficiency (%) 9 10 13 10 4 10 Heat storage (° C.) 51 52 53 52 50 52Weatherability ◯ ◯ ◯ ◯ ◯ X Water vapor barrier property (permeabilitytest: g/m² · d) 0.3 0.2 0.6 0.5 0.7 0.3 Comp. Comp. Comp. Comp. Comp.Ex. II-7 Ex. II-1 Ex. II-2 Ex. II-3 Ex. II-4 Ex. II-5 Layer Layer (A)Material PET-1 ASA-1 ASA-9 ASA-1 — ASA-1 constitution Tg (° C.) 75 135135 135 — 135 Pigment color Transmit- Transmit- CB Transmit- — Transmit-table table table table black black black black Thickness (μ) 40 30 3030 0 30 Layer (B) Material PET-3 ASA-3 ASA-3 — ASA-3 ASA-7 Tg (° C.) 75155 155 — 155 108 Pigment color — — — — White — Thickness (μ) 70 100 1000 200 100 Layer (C) Material PET-2 ASA-2 ASA-2 ASA-2 — ASA-2 Tg (° C.)75 135 135 135 — 135 Pigment color White White White White — WhiteThickness (μ) 40 100 100 200 0 60 Layer (D) Film Material WVB-1 — WVB-1WVB-1 WVB-2 WVB-1 Thickness (μ) 12 0 12 12 12 12 Adhesive Material Poly-— Poly- Poly- Poly- Poly- layer urethane urethane urethane urethaneurethane Thickness (μ) 3 0 5 3 3 5 Thickness of the whole layeredproduct (μ) 165 230 247 245 215 207 Difference between Tg of layer (B)and Tg of layer (A) (° C.) 0 20 20 — — −27 Difference between Tg oflayer (B) and Tg of layer (C) (° C.) 0 20 20 — — −27 Absorptance of alight with a wavelength of 800-1400 nm of 7 5 88 6 — 6 layer (A) alone(%) Reflectance of a light with a wavelength of 400-1400 nm of 72 87 8785 — 77 layer (C) alone (%) Evaluation L value of surface on the layer(A) side of layered product 25 27 25 28 — 27 results L value of surfaceon the layer (C) side of layered product 79 92 91 91 — 86 Heatresistance: dimensional change after 30 min. at 150° C. 0.4 0.4 0.4 1.40.3 1.5 of layer (B) alone (%) Flexibility (bending test) ⊚ ⊚ ⊚ ⊚ X ⊚Hydrolytic resistance 100 hours Retention of fracture stress X ◯ ◯ ◯ ◯ ◯(pressure cooker test) later Retention of elongation X ◯ ◯ ◯ ◯ ◯ 200hours Retention of fracture stress X ◯ ◯ ◯ ◯ ◯ later Retention ofelongation X ◯ ◯ ◯ ◯ ◯ Improvement rate of conversion efficiency (%) 9 90 10 14 10 Heat storage (° C.) 51 51 80 52 48 51 Weatherability X ◯ ◯ ◯◯ ◯ Water vapor barrier property (permeability test: g/m² · d) 0.1 4.30.4 0.3 0.6 0.5

The followings are clear from Table 5. Examples II-1 to II-7 involvingthe layered product comprising the layer (A), layer (B), layer (C) andlayer (D) of the present invention had an appearance which was coloredby allowing a color of the layer (A) to be seen through the layer (D),was excellent in flexibility and water vapor barrier property, good ininfrared transmittability, low in heat storage and excellent in heatresistance, and was improved in power generation efficiency. Also,Examples II-1 to II-5 involving use of a silicone/acrylic compositerubber-reinforced styrene resin or use of a mixture of a siliconerubber-reinforced styrene resin and an acrylic rubber-reinforced styreneresin for all the layer (A), (B) and (C) were further excellent inweatherability and hydrolytic resistance.

Comparative Example II-1 in which the layer (D) was omitted was inferiorin water vapor barrier property. Comparative Example II-2 involving useof the layer (A) in which an infrared absorbable carbon black was usedinstead of the infrared transmittable coloring agent was high in heatstorage and inferior in power generation efficiency. Comparative ExampleII-3 in which the present layer (B) was omitted was inferior in heatresistance. Comparative Example II-4 involving use without the layers(A) and (C) of a white sheet alone made of the present layer (B) thatfurther contained titanium oxide as a pigment was inferior inflexibility. Comparative Example II-5 in which the layer (B) did notsatisfy the requirement of heat resistance according to the presentinvention was inferior in heat resistance.

3-3. Examples III-1 to III-8, Comparative Examples III-1 to III-8

A film was produced as in the same manner as above in item 3-1 (ExamplesI-1 to I-7 and Comparative Examples I-1 to I-4) except that each pelletof the above layers (A), (B) and (C) was supplied to each extruder of amulti-layer film molding machine as shown in Table 6-1 or Table 6-2, andevaluated. The evaluation results of the resulting film are shown inTable 6-1 or Table 6-2.

TABLE 6-1 Ex. III-1 Ex. III-2 Ex. III-3 Ex. III-4 Ex. III-5 Ex. III-6Ex. III-7 Ex. III-8 Layer Layer (A) Material ASA-1 ASA-1 ASA-1 ASA-6ASA-1 ASA-1 ABS-1 PET-1 constitution Tg (° C.) 135 135 135 135 135 135135 75 Pigment color Transmit- Transmit- Transmit- Transmit- Transmit-Transmit- Transmit- Transmit- table table table table table table tabletable black black black black black black black black Thickness H_(A)(μ)20 60 90 50 40 120 60 50 Layer (B) Material ASA-3 ASA-3 ASA-4 ASA-3ASA-4 ASA-3 ABS-3 PET-3 Tg (° C.) 155 155 155 155 155 155 155 75 Pigmentcolor — — — — — — — — Thickness H_(B)(μ) 60 120 150 120 150 120 120 100Layer (C) Material ASA-2 ASA-2 ASA-2 ASA-2 ASA-8 ASA-2 ABS-2 PET-2 Tg (°C.) 135 135 135 135 135 135 135 75 Pigment color White White White WhiteWhite White White White Thickness H_(C)(μ) 20 60 90 60 50 120 60 50Thickness of the whole layered 100 240 330 230 240 360 240 200 product(μ) Difference between Tg of layer (B) and 20 20 20 20 20 20 20 0 Tg oflayer (A) (° C.) Difference between Tg of layer (B) and 20 20 20 20 2020 20 0 Tg of layer (C) (° C.) H_(A)/H_(C) 1.00 1.00 1.00 0.83 0.80 1.001.00 1.00 (H_(A) + H_(C))/H_(B) 0.67 1.00 1.20 0.92 0.60 2.00 1.00 1.00Evaluation Absorptance of a light with a 5 5 7 6 5 8 6 4 resultswavelength of 800-1400 nm of layer (A) alone (%) Reflectance of a lightwith a 75 88 90 85 80 92 83 79 wavelength of 400-1400 nm of layer (C)alone (%) L value of surface of layer (A) of 38 25 17 27 30 12 22 27layered product L value of surface of layer (C) of 72 84 90 85 83 92 8784 layered product Heat resistance: dimensional change 0.4 0.3 0.3 0.30.3 0.3 0.3 0.4 after 30 min. at 150° C. of layer (B) alone Heatresistance: dimensional change 0.4 0.3 0.3 0.3 0.3 0.3 0.3 0.4 after 30min. at 150° C. of layered product Flexibility (bending test) ⊚ ⊚ ⊚ ⊚ ⊚⊚ ⊚ ⊚ Hydrolytic 100 Retention of ◯ ◯ ◯ ◯ ◯ ◯ ◯ X resistance hoursfracture (pressure later stress cooker Retention of ◯ ◯ ◯ ◯ ◯ ◯ ◯ Xtest) elongation Curl ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ (deformation) condition 200Retention of ◯ ◯ ◯ ◯ ◯ ◯ ◯ X hours fracture later stress Retention of ◯◯ ◯ ◯ ◯ ◯ ◯ X elongation Curl ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ (deformation) conditionImprovement rate of 8 12 15 12 10 14 12 9 conversion efficiency (%) Heatstorage (° C.) 45 51 53 50 50 55 49 52 Weatherability ◯ ◯ ◯ ◯ ◯ ◯ X X

TABLE 6-2 Comp. Ex. Comp. Comp. Ex. Comp. Comp. Comp. Comp. Ex. Comp.III-1 Ex. III-2 III-3 Ex. III-4 Ex. III-5 Ex. III-6 III-7 Ex. III-8Layer Layer (A) Material ASA-9 ASA-1 — ASA-1 ASA-1 ASA-1 ASA-1 ASA-1constitution Tg (° C.) 135 135 — 135 135 135 135 135 Pigment color CBTransmit- — Transmit- Transmit- Transmit- Transmit- Transmit- tabletable table table table table black black black black black blackThickness H_(A) (μ) 60 70 0 60 40 140 35 100 Layer (B) Material ASA-3 —ASA-5 ASA-7 ASA-3 ASA-3 ASA-3 ASA-3 Tg (° C.) 155 — 155 108 155 155 155155 Pigment color — — White — — — — — Thickness H_(B) (μ) 120 0 150 120120 140 200 80 Layer (C) Material ASA-2 ASA-2 — ASA-2 ASA-2 ASA-2 ABS-2ASA-2 Tg (° C.) 135 135 — 135 135 135 135 135 Pigment color White White— White White White White White Thickness H_(C) (μ) 60 80 0 60 120 10035 100 Thickness of the whole layered 240 150 150 240 280 380 270 280product (μ) Difference between Tg of layer (B) 20 — — −27 20 20 20 20and Tg of layer (A) (° C.) Difference between Tg of layer (B) 20 — — −2720 20 20 20 and Tg of layer (C) (° C.) H_(A)/H_(C) 1.00 0.88 — 1.00 0.331.40 1.00 1.00 (H_(A) + H_(C))/H_(B) 1.00 — — 1.00 1.33 1.71 0.35 2.50Evaluation Absorptance of a light with a 90 6 — 5 4 9 5 9 resultswavelength of 800-1400 nm of layer (A) alone (%) Reflectance of a lightwith a wavelength 83 91 — 85 93 90 78 91 of 400-1400 nm of layer (C)alone (%) L value of surface of layer (A) of 22 18 — 21 31 12 35 12layered product L value of surface of layer (C) of 88 89 — 87 92 90 7390 layered product Heat resistance: dimensional change 0.3 — 0.3 1.3 0.30.3 0.2 0.5 after 30 min. at 150° C. of layer (B) alone Heat resistance:dimensional change 0.3 1.8 0.3 1.3 0.3 0.3 0.2 1.2 after 30 min. at 150°C. of layered product Flexibility (bending test) ⊚ ⊚ X ⊚ ⊚ ⊚ X ⊚Hydrolytic 100 Retention of ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ resistance hours fracturestress (pressure later Retention of ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ cooker elongationtest) Curl ◯ ◯ ◯ ◯ X X ◯ ◯ (deformation) condition 200 Retention of ◯ ◯◯ ◯ ◯ ◯ ◯ ◯ hours fracture stress later Retention of ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯elongation Curl ◯ ◯ ◯ ◯ X X ◯ ◯ (deformation) condition Improvement rateof 0 13 15 10 15 13 7 14 conversion efficiency (%) Heat storage (° C.)82 50 41 48 50 52 49 49 Weatherability ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯

The followings are clear from Tables 6-1 and 6-2. Examples III-1 toIII-8 involving the layered products comprising a layer (A), a layer (B)and a layer (C) of the present invention were excellent in flexibility,and were good in infrared transmittability, low in heat storage andexcellent heat resistance as layered products even though their surfacewas made from a colored resin, and were further prevented from curlingand improved in power generation efficiency. Also, Examples III-1 toIII-7 involving use of rubber-reinforced styrene resins for all thelayers (A), (B) and (C) were further excellent in hydrolytic resistance.Further, Examples III-1 to 111-6 in which a silicone/acrylic compositerubber-reinforced styrene resin or a mixture of a siliconrubber-reinforced styrene resin and an acrylic rubber-reinforced styreneresin was used for all the layers (A), (B) and (C) were furtherexcellent in weatherability.

Comparative Example III-1 involving use of an infrared absorbable carbonblack instead of the infrared transmittable coloring agent in the layer(A) was high in light absorptance in a wavelength of 800-1400 nm of thelayer (A) alone and inferior in heat storage and power generationefficiency. Comparative Example III-2 in which the present layer (B) wasomitted was large in dimensional change (%) of the layered product at150° C. for 30 minutes, and inferior in heat resistance of the layeredproduct. Comparative Example III-3 involving use of a layer (B) alonewhich further contained titanium oxide as a pigment was inferior inflexibility. Comparative Example III-4 involving use of a layer (B)which does not satisfy the requirement for heat resistance of thepresent invention was large in dimensional change (%) of the layer (B)alone at 150° C. for 30 minutes, and inferior in heat resistance of thelayered product. Comparative Examples III-5 and III-6, in which a ratio(H_(A)/H_(C)) of a thickness (H_(A)) of the layer (A) to a thickness(H_(C)) of the layer (C) was out of the inventive preferable range,caused curling. Comparative Examples III-7 and III-8, in which a ratio((H_(A)+H_(C))/H_(B)) of the total of a thickness (H_(A)) of the layer(A) and a thickness (H_(C)) of the layer (C) to a thickness (H_(B)) ofthe layer (B) was out of the inventive preferable range, were inferiorin either flexibility or heat resistance of the layered product.

3-4. Examples IV-1 to IV-8, Comparative Examples IV-1 to IV-9

A film was produced as in the same manner as above in item 3-2 (ExamplesII-1 to II-7 and Comparative Examples II-1 to II-4) except that eachpellet of the above layers (A), (B) and (C) was supplied to eachextruder of a multi-layer film molding machine as shown in Table 7-1 orTable 7-2, and evaluated. The evaluation results of the resulting filmare shown in Table 7-1 or Table 7-2.

TABLE 7-1 Ex. IV-1 Ex. IV-2 Ex. IV-3 Ex. IV-4 Ex. IV-5 Ex. IV-6 Ex. IV-7Ex. IV-8 Layer Layer (A) Material ASA-1 ASA-1 ASA-1 ASA-6 ASA-1 ASA-1ABS-1 PET-1 constitution Tg (° C.) 135 135 135 135 135 135 135 75Pigment color Transmit- Transmit- Transmit- Transmit- Transmit-Transmit- Transmit- Transmit- table table table table table table tabletable black black black black black black black black Thickness H_(A)(μ) 20 60 90 50 40 120 60 50 Layer (B) Material ASA-3 ASA-3 ASA-4 ASA-3ASA-4 ASA-3 ABS-3 PET-3 Tg (° C.) 155 155 155 155 155 155 155 75 Pigmentcolor — — — — — — — — Thickness H_(B) (μ) 60 120 150 120 150 120 120 100Layer (C) Material ASA-2 ASA-2 ASA-2 ASA-2 ASA-8 ASA-2 ABS-2 PET-2 Tg (°C.) 135 135 135 135 135 135 135 75 Pigment color White White White WhiteWhite White White White Thickness H_(C) (μ) 20 60 90 60 50 120 60 50Layer (D) Film Material WVB-1 WVB-1 WVB-2 WVB-2 WVB-2 WVB-2 WVB-1 WVB-1Thickness (μ) 12 12 12 12 12 12 12 12 Adhesive Material Poly- Poly-Poly- Poly- Poly- Poly- Poly- Poly- layer urethane urethane urethaneurethane urethane urethane urethane urethane Thickness (μ) 5 3 5 5 3 5 33 Thickness of the whole 117 255 347 247 255 377 255 215 layered product(μ) Difference between Tg of layer (B) 20 20 20 20 20 20 20 0 and Tg oflayer (A) (° C.) Difference between Tg of layer (B) 20 20 20 20 20 20 200 and Tg of layer (C) (° C.) H_(A)/H_(C) 1.00 1.00 1.00 0.83 0.80 1.001.00 1.00 (H_(A) + H_(C))/H_(B) 0.67 1.00 1.20 0.92 0.60 2.00 1.00 1.00Evaluation Absorptance of a light with a 5 5 7 6 5 8 6 4 wavelength of800-1400 nm of layer (A) alone (%) Reflectance of a light with a 75 8890 85 80 92 83 79 wavelength of 400-1400 nm of layer (C) alone (%) Lvalue of surface of layer (A) of 38 25 17 27 30 12 22 27 layered productL value of surface of layer (C) of 72 84 90 85 83 92 87 84 layeredproduct Heat resistance: dimensional change 0.4 0.3 0.3 0.3 0.3 0.3 0.30.4 after 30 min. at 150° C. of layer (B) alone (%) Heat resistance:dimensional change 0.4 0.3 0.3 0.3 0.3 0.3 0.3 0.4 after 30 min. at 150°C. of layered product (%) Flexibility (bending test) ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚Hydrolytic 100 hours Retention of ◯ ◯ ◯ ◯ ◯ ◯ ◯ X resistance laterfracture stress (pressure Retention of ◯ ◯ ◯ ◯ ◯ ◯ ◯ X cooker elongationtest) Curl ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ (deformation) condition 200 hours Retentionof ◯ ◯ ◯ ◯ ◯ ◯ ◯ X later fracture stress Retention of ◯ ◯ ◯ ◯ ◯ ◯ ◯ Xelongation Curl ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ (deformation) condition Improvement rateof 8 12 15 12 10 14 12 9 conversion efficiency (%) Heat storage (° C.)45 51 53 50 50 55 49 52 Weatherability ◯ ◯ ◯ ◯ ◯ ◯ X X Water vaporbarrier property 0.5 0.3 0.3 0.4 0.4 0.4 0.3 0.3 (permeability test:g/m² · d)

TABLE 7-2 Comp. Comp. Comp. Comp. Comp. Ex. IV-1 Ex. IV-2 Ex. IV-3 Ex.IV-4 Ex. IV-5 Layer Layer (A) Material ASA-1 ASA-9 ASA-1 — ASA-1constitution Tg (° C.) 135 135 135 — 135 Pigment color Transmit- CBTransmit- — Transmit- table table table black black black ThicknessH_(A) (μ) 60 60 70 0 60 Layer (B) Material ASA-3 ASA-3 — ASA-5 ASA-7 Tg(° C.) 155 155 — 155 108 Pigment color — — — White — Thickness H_(B) (μ)120 120 0 150 120 Layer (C) Material ASA-2 ASA-2 ASA-2 — ASA-2 Tg (° C.)135 135 135 — 135 Pigment color White White White — White ThicknessH_(C) (μ) 60 60 80 0 60 Layer (D) Film Material — WVB-1 WVB-1 WVB-2WVB-1 Thickness (μ) 0 12 12 12 12 Adhesive layer Material — Poly- Poly-Poly- Poly- urethane urethane urethane urethane Thickness (μ) 0 5 3 3 5Thickness of the whole layered product (μ) 240 257 165 165 257Difference between Tg of layer (B) and Tg of layer (A) (° C.) 20 20 — —−27 Difference between Tg of layer (B) and Tg of layer (C) (° C.) 20 20— — −27 H_(A)/H_(C) 1.00 1.00 0.88 — 1.00 (H_(A) + H_(C))/H_(B) 1.001.00 — — 1.00 Evaluation Absorptance of a light with a wavelength of800-1400 nm of layer (A) 6 90 6 — 5 results alone (%) Reflectance of alight with a wavelength of 400-1400 nm of layer (C) 82 83 91 — 85 alone(%) L value of surface of layer (A) of layered product 21 22 18 — 21 Lvalue of surface of layer (C) of layered product 87 88 89 — 87 Heatresistance: dimensional change after 30 min. at 150° C. of layer (B) 0.30.3 — 0.3 1.3 alone (%) Heat resistance: dimensional change after 30min. at 150° C. of layered 0.3 0.3 1.8 0.3 1.3 product (%) Flexibility(bending test) ⊚ ⊚ ⊚ X ⊚ Hydrolytic resistance 100 hours later Retentionof fracture stress ◯ ◯ ◯ ◯ ◯ (pressure cooker test) Retention ofelongation ◯ ◯ ◯ ◯ ◯ Curl (deformation) condition ◯ ◯ ◯ ◯ ◯ 200 hourslater Retention of fracture stress ◯ ◯ ◯ ◯ ◯ Retention of elongation ◯ ◯◯ ◯ ◯ Curl (deformation) condition ◯ ◯ ◯ ◯ ◯ Improvement rate ofconversion efficiency (%) 11 0 13 15 10 Heat storage (° C.) 50 82 50 4148 Weatherability ◯ ◯ ◯ ◯ ◯ Water vapor barrier property (permeabilitytest: g/m² · d) 41 0.4 0.3 0.3 0.4 Comp. Comp. Comp. Comp. Ex. IV-6 Ex.IV-7 Ex. IV-8 Ex. IV-9 Layer Layer (A) Material ASA-1 ASA-1 ASA-1 ASA-1constitution Tg (° C.) 135 135 135 135 Pigment color Transmit- Transmit-Transmit- Transmit- table table table table black black black blackThickness H_(A) (μ) 40 140 35 100 Layer (B) Material ASA-3 ASA-3 ASA-3ASA-3 Tg (° C.) 155 155 155 155 Pigment color — — — — Thickness H_(B)(μ) 120 140 200 80 Layer (C) Material ASA-2 ASA-2 ASA-2 ASA-2 Tg (° C.)135 135 135 135 Pigment color White White White White Thickness H_(C)(μ) 120 100 35 100 Layer (D) Film Material WVB-1 WVB-1 WVB-2 WVB-1Thickness (μ) 12 12 12 12 Adhesive layer Material Poly- Poly- Poly-Poly- urethane urethane urethane urethane Thickness (μ) 5 3 3 5Thickness of the whole layered product (μ) 297 395 285 297 Differencebetween Tg of layer (B) and Tg of layer (A) (° C.) 20 20 20 20Difference between Tg of layer (B) and Tg of layer (C) (° C.) 20 20 2020 H_(A)/H_(C) 0.33 1.40 1.00 1.00 (H_(A) + H_(C))/H_(B) 1.33 1.71 0.352.50 Evaluation Absorptance of a light with a wavelength of 800-1400 nmof layer (A) 4 9 5 9 results alone (%) Reflectance of a light with awavelength of 400-1400 nm of layer (C) 93 90 78 91 alone (%) L value ofsurface of layer (A) of layered product 31 12 35 12 L value of surfaceof layer (C) of layered product 92 90 73 90 Heat resistance: dimensionalchange after 30 min. at 150° C. of layer (B) 0.3 0.3 0.2 0.5 alone (%)Heat resistance: dimensional change after 30 min. at 150° C. of layered0.3 0.3 0.2 1.2 product (%) Flexibility (bending test) ⊚ ⊚ X ⊚Hydrolytic resistance 100 hours later Retention of fracture stress ◯ ◯ ◯◯ (pressure cooker test) Retention of elongation ◯ ◯ ◯ ◯ Curl(deformation) condition X X ◯ ◯ 200 hours later Retention of fracturestress ◯ ◯ ◯ ◯ Retention of elongation ◯ ◯ ◯ ◯ Curl (deformation)condition X X ◯ ◯ Improvement rate of conversion efficiency (%) 15 13 714 Heat storage (° C.) 50 52 49 49 Weatherability ◯ ◯ ◯ ◯ Water vaporbarrier property (permeability test: g/m² · d) 0.3 0.3 0.3 0.4

The followings are clear from Tables 7-1 and 7-2. Examples IV-1 to IV-8involving the layered products comprising a layer (A), a layer (B), alayer (C) and a layer (D) of the present invention had an appearancewhich was colored by allowing a color of the layer (A) to be seenthrough the layer (D), were excellent in flexibility and water vaporbarrier property, good in infrared transmittability, low in heat storageand excellent in heat resistance as a layered product, and wereprevented from curling and improved in power generation efficiency.Also, Examples IV-1 to IV-7 involving use of rubber-reinforced styreneresins for all the layer (A), (B) and (C) were further excellent inhydrolytic resistance. Further, Examples IV-1 to IV-6 in which asilicone/acrylic composite rubber-reinforced styrene resin or a mixtureof a silicon rubber-reinforced styrene resin and an acrylicrubber-reinforced styrene resin was used for all the layers (A), (B) and(C) were further excellent in weatherability.

Comparative Example IV-1 was an example in which the layer (D) wasomitted, and was inferior in water vapor barrier property. ComparativeExample IV-2 involving use of an infrared absorbable carbon blackinstead of the infrared transmittable coloring agent in a layer (A) washigh in light absorptance in a wavelength of 800-1400 nm of the layer(A) alone, and was inferior in heat storage and power generationefficiency. Comparative Example IV-3 in which the layer (B) of thepresent invention was omitted was large in dimensional change (%) of thelayered product at 150° C. for 30 minutes, and inferior in heatresistance of the layered product. Comparative Example IV-4 involvinguse without the layers (A) and (C) of a layer (B) alone which was awhite sheet further containing titanium oxide as a pigment was inferiorin flexibility. Comparative Example IV-5 involving a layer (B) which didnot satisfy the requirement for heat resistance of the present inventionwas large in dimensional change (%) of the layer (B) alone at 150° C.for 30 minutes, and inferior in heat resistance of the layered product.Comparative Examples IV-6 and IV-7, in which a ratio (H_(A)/H_(C)) of athickness (H_(A)) of the layer (A) to a thickness (H_(C)) of the layer(C) was out of the inventive preferable range, caused curling.Comparative Examples IV-8 and IV-9, in which a ratio((H_(A)+H_(C))/H_(B)) of the total of a thickness (H_(A)) of the layer(A) and a thickness (H_(C)) of the layer (C) to a thickness (H_(B)) ofthe layer (B) was out of the inventive preferable range, were inferiorin either flexibility or heat resistance of the layered product.

3-5. Examples I-8 and I-9

A PET film of Table 8 was stuck on the outer surface of the layer (C) ofthe film obtained in Example I-2 using a polyurethane adhesive agent(painting thickness: 8 μm). Using the resulting film and the filmobtained in Example I-2 as test pieces, flame resistance and scratchresistance were evaluated in accordance with the above methods. Theresults are shown in Table 8.

TABLE 8 Example Example Example I-2 I-8 I-9 Material of the none (E-1)(E-2) protective layer (E) Scratch resistance Δ ∘ ∘ Flame resistance x ∘∘

From Table 8, it is found that scratch resistance and flame resistanceare imparted by laminating a protective layer on the layered product ofthe present invention, and this is preferable.

3-6. Example II-8

A film was produced in the same manner as in Example II-2 except that awater vapor barrier layer (D) was layered on the outer surface of thelayer (C). In this instance, the layer (D) was layered so that the thinfilm layer (water vapor barrier layer) of the water vapor barrier filmconstituting the layer (D) was positioned to form the outermost surface.That is, the layered product with a structure shown in FIG. 2 wasobtained.

Using the resulting film and the film obtained in Example II-2 as testpieces, flame resistance and scratch resistance were evaluated inaccordance with the above methods. The results are shown in Table 9.

3-7. Example II-9

A PET film of Table 9 was stuck as the protective layer (E) on the outersurface of the layer (C) of the film obtained in Example II-2 using apolyurethane adhesive agent (painting thickness: 8 μm). That is, thelayered product with a structure shown in FIG. 3 was obtained.

Using the resulting film as a test piece, flame resistance and scratchresistance were evaluated in accordance with the above methods. Theresults are shown in Table 9.

3-8. Example II-10

A PET film of Table 9 was stuck as the protective layer (E) on the outersurface of the layer (D) of the film obtained in Example II-8 using apolyurethane adhesive agent (painting thickness: 8 μm). That is, thelayered product with a structure shown in FIG. 4 was obtained.

Using the resulting film as a test piece, flame resistance and scratchresistance were evaluated in accordance with the above methods. Theresults are shown in Table 9.

TABLE 9 Example Example Example Example II-2 II-8 II-9 II-10 Material ofthe none none (E-1) (E-1) protective layer (E) Scratch resistance Δ Δ ∘∘ Flame resistance x x ∘ ∘

From Table 9, it is found that scratch resistance and flame resistanceare improved by laminating a protective layer (E) of the presentinvention on the outer surface of the layer (C), and this is preferable.

INDUSTRIAL APPLICABILITY

The infrared reflective layered product of the present invention has acolored resin surface, has a property of reflecting an infraredradiation to prevent heat storage, and is excellent in heat resistance,and further can be one excellent in weatherability, hydrolyticresistance and flexibility, and furthermore can have an excellent watervapor barrier and/or can be prevented from curing. Thus, it can beutilized as a back sheet for solar cells used under severe environmentexposed to sunlight, as well as a material of parts which requireinfrared reflectivity under severe environment at high temperature.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross sectional view showing a preferable embodiment of thelayered product of the present invention.

FIG. 2 is a cross sectional view showing another preferable embodimentof the layered product of the present invention.

FIG. 3 is a cross sectional view showing the embodiment of FIG. 1,provided with a protective layer.

FIG. 4 is a cross sectional view showing the embodiment of FIG. 2,provided with a protective layer.

DESCRIPTION OF SYMBOLS

A: Layer (A), B: Layer (B), C: Layer (C), D: Layer (D), E: Layer (E),D1: Synthetic resin film, D2: Thin film layer, S: Solar battery siliconcell

1-18. (canceled)
 19. An infrared reflective layered product selectedfrom the group consisting of: an infrared reflective layered productcomprising: a layer (B) as a base layer; a layer (A) layered on one sideof the layer (B); and a layer (C) as a light reflecting layer that islayered on the other side of the layer (B), wherein the layer (A) is acolored resin layer having an absorptance of a light with a wavelengthof 800-1400 nm of not more than 10% and is made from a resin containingan infrared transmittable coloring agent, the layer (B) is an infraredtransmittable thermoplastic resin layer which shows a dimensional change(s) satisfying 1%≧s≧−1% when left at 150° C. for 30 minutes, the layer(C) is a colored resin layer having a reflectance of a light with awavelength of 400-1400 nm of not less than 50%, and is made from a resincontaining a while pigment, and the infrared reflective layered producthas an L value (brightness) of the surface on the layer (A) side thereofof not more than 40, and has an L value (brightness) of the surface onthe layer (C) side thereof of not less than
 70. 20. The layered productaccording to claim 19, wherein the layer (A) has a thickness (HA), thelayer (B) has a thickness (HB), and the layer (C) has a thickness (HC),whereby the following expressions (2) and (3) are satisfied:0.5≦H _(A) /H _(C)<1.3  (2)0.4≦(H _(A) +H _(C))/H _(B)≦2.4  (3).
 21. The layered product accordingto claim 20, wherein the following expression (2′) is satisfied:0.75≦H_(A)/H_(C)≦1.25  (2′).
 22. The layered product according to claim20, wherein the layer (B) is made from a thermoplastic resin (I) with aglass transition temperature of not less than 120° C., and the layer (A)and the layer (C) are made from a thermoplastic resin (II) having aglass transition temperature lower than the thermoplastic resin (I). 23.The layered product according to claim 22, wherein said thermoplasticresin (II) is a styrene resin (II-1) which comprises a rubber-reinforcedstyrene resin (II-1-1) obtained by polymerization of a vinyl monomer (b)comprising an aromatic vinyl compound and optionally another monomercopolymerizable with the aromatic vinyl compound in a presence of arubber-like polymer (a), and optionally comprises a (co)polymer (II-1-2)of a vinyl monomer (b), the content of the rubber-like polymer (a) being5-40 parts by mass relative to 100 parts by mass of the styrene resin(II-1).
 24. The layered product according to claim 23, wherein saidrubber-like polymer (a) is at least one selected from the groupconsisting of ethylene-α-olefin rubbers, hydrogenated conjugated dienerubbers, acrylic rubbers, silicone rubbers and silicone/acryliccomposite rubbers.
 25. The layered product according to claim 24,wherein the vinyl monomer (b) constituting said styrene resin (II-1)comprises a maleimide compound unit, the content of the maleimidecompound unit being 1-30 mass % relative to 100 mass % of the styreneresin (II-1).
 26. The layered product according to claim 22, whereinsaid thermoplastic resin (I) is a vinyl resin (I′) which comprises arubber-reinforced vinyl resin (I-1) obtained by polymerization of avinyl monomer (ii) in a presence of a rubber-like polymer (i) andoptionally a (co)polymer (I-2) of a vinyl monomer (ii), the content ofthe rubber-like polymer (i) being 5-40 parts by mass relative to 100parts by mass of the thermoplastic resin (I).
 27. The layered productaccording to claim 26, wherein said rubber-like polymer (i) is at leastone selected from the group consisting of ethylene-α-olefin rubbers,hydrogenated conjugated diene rubbers, acrylic rubbers, silicone rubbersand silicone/acrylic composite rubbers.
 28. The layered productaccording to claim 26, wherein a vinyl monomer (ii) constituting saidthermoplastic resin (I) comprises a maleimide compound unit, the contentof the maleimide compound unit being 1-30 mass % relative to 100 mass %of the thermoplastic resin (I).
 29. The layered product according toclaim 22, wherein said thermoplastic resin (I) has a glass transitiontemperature (Tg (I)) of 120-220° C., and said thermoplastic resin (II)has a glass transition temperature (Tg (II)) satisfying the followingexpression (1)(Tg(I)−Tg(II))≧10° C.  (1).
 30. The layered product according to claim19, wherein said layered product comprises a protective layer (E)provided on the outer surface of the layer (A) and/or the outer surfaceof the layer (C).
 31. The layered product according to claim 19, whereinsaid layered product further comprises a water vapor barrier layer (D)layered on the outer surface of said layer (A) or said layer (C), orbetween said layer (A) and said layer (B) or between said layer (B) andsaid layer (C).
 32. The layered product according to claim 31, whereinsaid layered product further comprises a protective layer (E) which isprovided on the layer (C) side as an outermost layer.
 33. The layeredproduct according to claim 19, wherein the layer © is a colored resinlayer having a reflectance of a light with a wavelength of 400-1400 nmof nor less than 60%.
 34. The layered product according to claim 19,wherein the layer (C) is a colored resin layer having a reflectance of alight with a wavelength of 400-1400 nm of not less than 70%.
 35. Thelayered product according to claim 19, wherein the layer (C) is acolored resin layer having a reflectance of a light with a wavelength of400-1400 nm of not less than 80%.
 36. The layered product according toclaim 19, wherein the layer (C) is a colored resin layer having areflectance of a light with a wavelength of 400-1400 nm of at least 95%.37. A solar cell back sheet comprising the layered product according toclaim
 19. 38. A solar cell module comprising the solar cell backsheetaccording to claim 37.